Packing-House Industries 



By 

L. M. TOLMAN 

CHIEF CHEMIST, WILSON & CO. 



PACKING-HOUSE INDUSTRIES 
Parts 1-3 



392 

Published by 
INTERNATIONAL TEXTBOOK COMPANY 

SCRANTON, PA. 



t\\t, 



T' 



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Packing-House Industries, Parts 1, 2, and 3: Copyright. 1922, 1909, 1902. by Inter- 
national Textbook Company. 



Copyright in Great Britain 



All rights reserved 



Printed in U. S. A. 



International Textbook Press 
Scranton, Pa. 



70760 






CONTENTS 



Note. — This book is made up of separate parts, or sections, as indicated by 
their titles, and the page numbers of each usually begin with 1. In this list of 
contents the titles of the parts are given in the order in which they appear in the 
book, and under each title is a full synopsis of the subjects treated. 



U3 



PACKING-HOUSE INDUSTRIES, PART 1 

Pages 

Introduction 1_ 5 

History of the industry; Breadth of the packing indus- 
try; Method of conducting establishments. 

Meat Inspection 7 

Various Animal Products and Their Disposition 8-59 

Beef Products 8-20 

Hide; Head; Tongue; Liver; Heart; Tail; Tripe; Sweet- 
breads; Beef gall; Feet; Casings; Fat; Horns and 
horn piths ; Blood ; Fertilizer materials. 

Hogf Products 21-27 

Calf Products 27 

Sheep Products 28-29 

Goats 30 

Processes for the Manufacture of Lard 30 

Steam-Rendered Lard 31^2 

Rendering tank; Precautions for safety of tanks; Opera- 
tion of steam rendering for the production of prime 
steam lard ; New rendering methods ; Operation of 
Wannenwetch system ; Advantages of new system. 

Refined Lard 42-46 

Bleaching with fuller's earth; Conditions for satisfac- 
tory bleaching; Lard coolers; Lard roll. 

Kettle-Rendered Lard 47-48 

Neutral Lard 49-52 

Process of manufacure ; Packing and graining; Grades 
and properties of neutral lard; Uses. 

Stififened Lards 53-56 

Edible Compounds 57-59 



iv CONTENTS 



PACKING-HOUSE INDUSTRIES, PART 2 

Pages 
Various Animal Products and Their Disposition 

(Continued) 1-61 

The Filter Press in the Packing House • 1-4 

Construction of filter press; Filter-press cloth; Opera- 
tion of filter press. 

Tallows, Greases, and Oils 5-30 

Kinds of Tallow 5- 9 

Edible tallow; Extra-prime tallow; No. 1 tallow; No. 2 
tallow; Cake tallow; Mutton tallow; Yield of tallow. 

Greases 10-1 1 

Classification; Grade A white grease; Grade B white 
grease; Yellow grease; Brown grease; Methods of 
obtaining grease. 

Oils 12-30 

Kinds; Oleo oil; Manufacture of oleo oil; Pressing the 
oleo stock; Oleo stearin; Neatsfoot oil; Lard oils; 
Lard and grease stearins; Tallow oil; Acidless tallow 
oil; Tallow stearin; Bleaching of oils; Bleaching test. 

Beef Extract 31-38 

Meat Canning 39-48 

Butterine 49-51 

Composition; Ingredients used; Churning and finishing. 

Glue 52-61 

Glue stock; Bone glue liquor; Horn-pith glues and gela- 
tines ; Head-glue liquor ; Clarification of glues ; 
Bleaching glue liquors ; Preservatives used in glues ; 
Concentration of glue liquors; Cutting glues; Yield 
of glues. 



CONTENTS 



PACKING-HOUSE INDUSTRIES, PART 3 

Pages 
Various Animal Products and Their Disposition 

(Continued) • 1-32 

Cured Meats 1-3 

Dry-salt meats ; Wet-cured meats ; Box-cured meats ; 
Vinegar-cured meats ; Smoked meats. 

Blood Albumin 4-6 

Digestive Ferments 7-13 

Pepsin; Purified pepsin; Powdered pepsin; Yield of pep- 
sin ; Valuation of pepsin ; Apparatus for making pep- 
sin; Peptone; Beef peptone; Pancreatin; Rennet. 

Animal Extracts 14 

Tankages and Fertilizers 15-17 

Tankage; Pressing tankage; Drying the pressed tankage; 
Grading of tankage ; Concentrated tankage ; Ground 
blood ; Raw bone and raw-bone meal ; Steamed bone 
and ground steamed bone ; Cooking bones for the 
recovery of tallow and steamed bone ; Cooking bones 
for the recovery of tallow, glue liquors, and steamed 
bone; Azotine; Hoof meal. 

Mixed Fertilizers 27-32 

Analytical Methods and Tests of Products 33-59 

Determination of Grade of Oils, Tallov^s, Greases, 

Etc 33-54 

Methods of Fertilizer Analysis 54-59 

Determination of moisture ; Preparation of solutions ; 
Determination of phosphoric acid; Determination of 
nitrogen; Determination of potash; Determination of 
crude fat or ether extract. 



PACKING-HOUSE INDUSTRIES 

(PART 1) 

Serial 414A Edition 3 

INTRODUCTION 

1. Historical. — The packing industry is said to have 
been carried on in the New England States as early as 1640, 
but not in the same way in which the modem business is con- 
ducted. The oldest record of su,ch an establishment per- 
petuated to this day, is claimed by a Philadelphia firm which 
started packing in the piamitive way of the times in 1760 and 
developed its methods into those of the modem packing hou,se. 

The packing industry with its diversified components as 
now understood dates from the year 1818 when an establish- 
ment was started in the city of Cincinnati, which soon became 
the center of this industry. One reason for this was the 
surrounding corn-raising area — the natural territory for a 
steady supply of hogs. As the population and facilities for 
shipping increased, the corn-belt area moved farther west, 
followed by the packing houses locating near their supply of 
raw material. Chicago, being situated in the corn-raising area 
and having natural transportation facihties because of its 
location at the head of Lake Michigan, followed Cincinnati as 
the center of the packing industry and is now indisputably 
and universally acknowledged as the center of the meat 
industries of the world. Thousands of cars of cattle and hogs, 
both live and dressed, are shipped from Chicago 'annually in 
addition to those animals slaughtered for consimiption in the 
immediate vicinity. 

Within the last few years large and important interests 
have developed in the packing industry farther west, notably 

COPYRIGHTED BY INTERNATIONAL TEXTBOOK COMPANY. ALL. RIGHTS RESERVED 



2 PACKING-HOUSE INDUSTRIES, PART 1 

in St. Louis, Omaha, St. Joseph, and Kansas City, for the 
obvious reason of the close proximity of suppHes of cattle and 
hogs raised in the sparsely settled Western States. Although 
these cities are large packing centers, Chicago, mainly on ac- 
count of its prestige and almost unequaled water and rail 
shipping facilities, still maintains its supremacy. 

Still more recently the packing industry has spread farther 
to the southwest, even into Texas, because of the modern 
tendencies in business to establish the manufactory at the base 
of supply of the raw material — in this industry, the live animals 
for slaughter. 

2. The primitive methods of this business have practically 
been revolutionized. In former times, natural temperatures 
and ice were the only available means for preserving the manu- 
factured products, in consequence of which the packing was 
carried on in the winter months only. Artificial refrigeration 
and the power to control temperatures, however, have made it 
possible for this industry to be carried on throughout the year. 
In addition to this, it is now possible to consume in the great 
consuming centers the meat of animals which are slaughtered 
thousands of miles away. It is transported in scientifically 
built refrigerator cars, a thing unknown until a few years ago. 

In addition to artificial refrigeration, another influential 
factor in developing the modem, scientific packing industry, 
is applied chemistry. If it were not for the ingenuity of the 
chemist, who finds a way to utilize the offal of slaughtered 
animals, the price of meat would be much higher. The chemist 
has turned into practical channels of income what was formerly 
not only waste but a source of expense for its removal. 

The object of the primitive packing industry was simply to 
produce meat. The object of the present scientific packing 
industry is not only to produce meat but also to utilize every 
available part of the animal. This objective is now attained 
to the highest degree in the large modern packing houses. 

3. Breadth of tlie Packing Industry. — The packing 
industry is so very broad that at present it covers an enormous 
field. Not only does the modern packing house pack pork 



PACKING-HOUSE INDUSTRIES, PART 1 3 

and beef in the same manner as when this industry was started 
on a large scale, but it also produces and handles many foods 
other than those produced from livestock. 

The modern packing establishment may be termed, in com- 
mon language, a food factory. Animal and vegetable foods and 
compounds of the two are produced in many forms ; in addition 
other edible compounds which verge closely on the pharma- 
ceutical field are also produced. This is evidenced by the pro- 
duction of beef extract, which, as prepared in the packing house, 
may hardly be considered a food but rather a stimulant. 

A step farther than this are the preparations known as 
digestive ferments, not food, but still alimentary products. 
Still further bordering on the pharmaceutical field are the 
preparations frequently produced (in the largest establish- 
ments), such as inspissated ox gall and the so-called animal 
extracts, as pituitary extract, adrenaline, thyroid extract, and 
other gland and tissue extracts. 

4. There are so many offshoots in the modem packing 
industry that it is difficult, in fact, to draw a. line where this 
industry ends. So many by-products of the animals slaughtered 
are now made into finished products by the packers that the 
tendency is to handle in one establishment the entire product 
and by-product of the slaughtered animals. 

When the slaughtering business first became established on 
a large scale there grew up in the vicinity of the packing plants 
independent establishments the purpose of which was the 
handling of the by-products collected from the packing houses. 
Glue works, fertilizer works, soap factories, oil and tallow 
works, and the like were in a large measure separate from the 
slaughtering concerns. As the packing business developed on 
modem and scientific lines and became concentrated in the 
hands of the larger companies, the allied industries were 
gradually — but, finally, almost completely — taken over by 
them. Various important economies were thus effected by 
unification and are being further effected from time to time. 

At the present time, the leading and largest packers carry 
the elaboration of almost every possible by-product to an 



4 PACKING-HOUSE INDUSTRIES, PART 1 

advanced stage. Frequently, the elaboration is carried out 
to the finished article of the product or by-product, so that it 
goes directly from the packer to the consumer, as evinced by 
the manufacture of such things as sandpaper, glue, sizing, 
hair felt, curled hair, anhydrous ammonia, finished fertilizer, 
soap, pepsin, etc. No matter how the various packing houses 
may differ in the degree to which finished products are made 
from their material, they are all actuated by one principle — - 
they do not permit anything of value to be wasted. 

5. The meat-canning industry is closely associated and 
nearly always contiguous to the packing house both for con- 
venience and for profit. This industry is complete in itself, 
although it is practically inseparable from the packing-house 
proper. The canning industry will therefore be described, as 
the economical management of the modem packing house 
depends to a very large extent on this resourceful branch of 
the business. 

The most important feature in the utilization of by-prod- 
ucts in the packing house is observed in the fertilizer depart- 
ment, as here all animal products which are not useful for food 
or manufacturing purposes are converted into a remunerative 
article — ^fertilizer — either finished, that is, complete fertilizer, 
or the crude form, known as tankage. This subject will be 
treated in its proper place. The establishing of this depart- 
ment may be said to mark the transition of the simple slaughter 
house of former days to the modern packing house in all its 
phases. Formerly, dressed meat only was produced, and the 
offal was a source of expense and encimibrance to the packer 
who willingly paid for having it taken away. With the knowl- 
edge acquired from the utilization of one by-product, as a 
natural consequence the utilization of all followed. 

The establishment of the glue department by the packing 
houses as a necessary adjunct is among the comparatively 
recent innovations as well as one of the most important. This 
subject will be treated at length under its proper caption, as 
will also various other industries that are closely associated 
with it 



PACKING-HOUSE INDUSTRIES, PART 1 5 

6. The development of the packing industry as it now 
exists is due in great measure to the knowledge and research 
of the packing-house chemist. Not only has the chemist 
aided this development, but he is engaged in furthering still 
more the utilization of the various waste products. In addi- 
tion to this, the modem packer depends on chemistry to aid 
him in conducting the whole industry on an economical and 
profitable basis. 

This will be readily apparent when the many operations 
are described in which chemistry plays such an important 
part in determining the grade or class and, consequently, the 
price of the finished product. The chemist of the packing 
house is daily called on to perform tests and analyses by 
which each day's output is controlled. For example, the 
amount of tallow or grease remaining in the cooked offal is 
such an important item that a daily report on the percentage 
left in this material is given to the superintendent. This one 
feature alone may be the cause of profit or an immense loss to 
the establishment. This shows the importance of applied 
chemistry in this industry. 

The field for the chemist in the development of by-products is 
most inviting and offers unlimited opportunity for the research 
and development of industrial and other uses for the offal. 

7. Method of Conducting Establishments. — The 

modem, large packing house in every department is conducted 
on strictly business principles. The different departments are 
regarded as independent concerns, the raw material received 
by each department being considered as purchased from an 
independent source, and the cost price charged up to its 
account. At the same time the department furnishing the 
material is credited with the price charged. The finished 
product turned out by each separate department when sold 
has the amount received credited to that department. All 
supplies, labor, utensils, etc. constitute a direct charge to the 
department receiving them; and, in addition, to each is appor- 
tioned pro rata, insurance, taxes, cartage, steam, light, office, 
selling expenses, etc. In this way it is ascertained what each 



6 PACKING-HOUSE INDUSTRIES, PART 1 

department is contributing to the general profit or loss. Each 
day a report of its receipts, shipments, labor, etc. is gi\^en to 
the general manager, who in the summary is thus enabled at 
a glance to see the status and condition of the whole establish- 
ment. The labor cost is closely scrutinized and should it be 
found that this is in excess of the regulation established, an 
investigation immediately results and an explanation is ob- 
tained. From years of experience and by frequent tests made 
in all departments of the establishment, the exact cost of each 
product and by-product is accurately known and regulated. 
Constant investigations with a view to perfecting methods and 
curtailing wastes, are being made, and new avenues are found for 
the further profitable working and disposition of by-products. 

8. In no business is more attention given to detail and there 
probably is no business where the average profit on each indi- 
vidual product is so small that the slightest inattention to 
detail results in serious losses. There have been periods in the 
packing industry when operations have been carried on in 
almost every department at a positive loss; but as so much 
machinery and apparatus are required in this industry, the 
small loss incurred from operating was far less than would 
have resulted from idle machinery, rusty tanks, etc. It may 
be truthfully said that of all departments of this industry 
there is only one from which a good profit is always expected 
and generally obtained, namely, the sausage department. This 
branch of the industry has the advantage of being able to 
utilize parts from all slaughtered animals passing the necessary 
inspection, while the other departments manufacturing the 
goods are restricted to a particular class of material. 

The general methods of treating and caring for packing- 
house products and by-products will be presented as they are 
daily carried out in the modern packing houses in the United 
States. If it were not for the utilization of by-products 
dressed beef would have to be sold at a much higher price. 
Broadly speaking, the vakie of beef from the average steer is 
about three-fourths of the total value of the products obtained 
from the animal. 



PACKING-HOUSE INDUSTRIES, PART 1 



MEAT INSPECTION 

9. In 1906 owing to various loose and negligent methods 
and practices in many packing houses, a most rigid govern- 
ment inspection law covering the whole packing and slaughter- 
ing industry was passed by Congress and went into effect on 
October 1 of that year. This law was enacted for the purpose 
of preventing in interstate or foreign commerce the use of 
meat and meat-food products that are unsound, unhealthful, 
unwholesome, or otherwise unfit for human food, under the 
authority conferred on the Secretary of Agriculture by the 
provisions of the act of Congress approved June 30, 1906. 

Regulations are prescribed for the inspection, reinspection, 
examination, supervision, disposition, and method and manner 
of handling of live cattle, sheep, swine, and goats, and the 
carcasses and meat-food products of cattle, sheep, swine, and 
goats, and for the sanitation of the establishments at which 
inspection is maintained. These regulations supersede those of 
1897 and those of 1904, excepting portions of the latter law and 
amendments that relate to the microscopic inspection of pork. 

As the law of 1906 made necessary extreme and radical 
changes in many of the products, their nomenclature, and 
methods of preparation, and as this law has such a direct 
bearing on the whole industry, the regulations governing 
the meat inspection of the United States Department of 
Agriculture are given in an accompanying pamphlet. 

A national pure-food law was also enacted in 1906. This 
law likewise has a direct bearing on many of the products 
emanating from the packing house, especially as relating to 
the names under which the prepared food products are sold. 

The new meat-inspection law and the national pure-food 
law, the latter known at the Food and Drugs Act, are corre- 
lated in many respects as applied to food products made in 
the packing house; hence the rulings and interpretations of 
the law as applied to these products are also given. 



8 PACKING-HOUSE INDUSTRIES, PART 1 

While the use of preservatives in food products for 
domestic consumption is prohibited, the law permits the use 
imder certain restrictions of preservatives in meat and meat- 
food products for export, but does not permit the use of any 
dye or coloring matter not permitted in meats prepared for 
interstate trade. 

VARIOUS ANIMAL PRODUCTS AND 
THEIR DISPOSITION 



BEEF PRODUCTS 

10, The disposition of a bullock in the modem packing 
house is quite complex. To obtain the best financial results, 
the operations of caring for the various by-products are carried 
out in great detail. By referring to the chart, Fig. 1, it will 
be seen into what products a bullock is ordinarily resolved. 
It is important for a chemist dealing with animal products to 
know the source and nature of material with which he has to 
deal. Further than this, knowing the characteristics of certain 
products, he can very often, by a superficial examination of 
material in question, at once name the source of its derivation. 

This is especially true of tallow and lard. Certain parts of 
animal fats have, as is well known, different melting points. 
For example, the tallow obtained from a bullock's head will 
have a titer, or hardness, not exceeding 41.5° or 42° C, while 
the tallow from the small intestines will have one of about 
44° C. When an ordinary tallow is found with a hardness of 
over 44° C, the origin is at once placed to the fat of the kidneys. 

11. The resolution of the bullock will be treated first, 
that of the hog afterward. While the chart, Fig. 1, shows 
the detail in a general way, some of the by-products are sub- 
divided still further. The method of handling in the par- 
ticular packing house determines this. For example, as shown 
in the chart, the feet, among other things, yield sinews, neats- 
foot oil, and raw bone. Taking these products, it is possible 
by further treatment of sinews to obtain glue, neatsfoot oil. 



<i 



THE DISPOSITION OF A BULLOCK IN THE PACKING HOUSE 



A Bullock Yields 

■ I 



Dressed Beef 



Food Products Manufactured Goods 

I (Food Containers) 



Scrap Tallow 

(Fertilizer Material) 



Oleo Stock Tripe Heart Liver Tail 



Fertilizer Material 



Hoofs Neatsfoot Raw G\ue Tankaere Sinews 

Oil Bone Liquor 



Tallow Tallow Oleo Oleo 

Oil Stearin Oil Stearin 



Sausage Weasand Bladder 
Casings 



Tank Tankage Tallow, 
Water Soap 



Tongue Meat Tallow Raw Glue Tankage ^ Horns 

^ Bone Liquor Horn Pith 



I L T 321 BB 392 414A 



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PACKING-HOUSE INDUSTRIES, PART 1 9 

and tankage. From the neatsfoot oil cold-pressed neatsfoot 
oil and neatsfoot stearin may be obtained. From the raw 
bone gelatine, glue, tallow, and bone meal are made. Thus, 
while the chart represents approximately the ultimate dis- 
position of the by-products, it should be remembered that 
further treatment is frequently practiced, even to the finished 
stage, as previously mentioned; also, that not all these 
by-products are made in all establishments. As the present 
conditions in this business, however, demand the utilization 
in the same plant of everything possible, the treatment of 
each product will be described. 

12. Hide. — Of the varied by-products from the bullock, 
the hide is the most valuable. It is removed from the freshly 
slaughtered bullock on the killing floor, usually located on an 
upper floor of the building, and conducted by chutes to the 
hide cellar. The hide cellar, as the name indicates, is located 
in the lowest level of the building where there is a cool fairly 
even temperature with a minimum of artificial refrigeration. 
After being trimmed free from adhering flesh and fat, it is 
allowed to cool for several hours to eliminate animal heat. If 
this were not done and the hide salted more or less warm, 
decomposition would tend to ensue, which, while held in check 
by the salt, would so injure the fiber of the hide that the tan- 
ner would be unable to make good leather of it. When such 
decomposition takes place, it also destroys the epidermis of the 
hide, causing more or less of the hair to come off in patches, and 
thus making a hair-slipped hide, much deteriorated in value. 

When cool, the hides are put into packs 30 to 40 feet square 
and several feet in height. Each hide, as it is spread on the 
pack, has spread over it a weight of salt approximately the 
same as that of the hide itself. While the hides are con- 
sidered as cured after a month in the pack, they are often 
allowed to remain there much longer. The hides are then 
termed green-salted and are put into one of several grades 
depending on weight, size, brand, and general condition. 

During the period of curing, considerable shrinkage takes 
place, the amount of which depends on the length of time in 



10 PACKING-HOUSE INDUSTRIES, PART 1 

the pack, the condition at the time of going into pack, and the 
amount of moisture in the hide cellar. The shrinkage varies 
from 14.3 to 15.8 per cent, and may show a variation with 
the time of year. 

A great deal of damage is done to hides by so-called salt 
stains, the true cause of which has not yet been determined. 
These stains may cause hides to go into cheaper grades of 
leather than would be necessary were they unstained, with a 
subsequent loss to packer and tanner. The best authorities 
seem to be of the opinion that the stains are caused by iron 
in the blood of the bullock. These stains are increased or 
exaggerated by resalting and by lying too long in the pack. 

13. Head. — ^After removal from the body, the head is 
trimmed free from meat, which is utilized in the making of 
sausages and for canning. Owing to the very gelatinous, or 
glutinous, character of this meat, it is valuable also for use in 
making other food products, as meat loaf, etc., in combination 
with other materials. 

The horns are sawed off. Horns constitute a very profit- 
able by-product of the packing house, as they bring good 
prices. Inside the horn is a tough, porous, semibony fill- 
ing termed horn pith, which is an excellent material for 
the making of high-grade edible gelatine. The piths are 
removed from the horns by means of hot water and are 
dried carefully. 

14, The head is separated into the skull and the jaw bone, 
after which the brain is removed from the skull, if desired for 
edible purposes, and the skull is placed in a vat of hot water. 
The jaw bone is cracked, so that the tallow contained in it 
can be boiled out and placed in the vat with the skull. After 
accumulating a quantity of bones in this manner, they are 
washed so as to remove the adhering blood and dirt, and boiled 
with live steam for about 10 hours. After this the vat is 
allowed a period of rest to permit the tallow to rise. This 
treatment yields tallow which is removed from the top of the 
liquor, and a watery solution of glue known as glue liquor, the 
treatment of which will be described later. 



PACKING-HOUSE INDUSTRIES, PART 1 11 

The bones remaining in the vat are removed and subse- 
quently freed from adhering meaty matter, washed, and dried 
on steam coils. They may be disposed of in this condition or 
they may be crushed by a bone crusher and made into crushed 
raw bone, or the latter may be put through a bone mill and 
ground into raw-bone meal. An analysis of this will show, 
approximately, ammonia 5 to 5§ per cent, and bone phosphate 
55 per cent. 

The meaty material from the heads and the small, thin 
bones left behind, are then put into a rendering tank, to obtain 
whatever tallow may be left in them. It has a titer test of 
about 41.5° C, the free acid, if the heads have been cooked 
fresh, not exceeding .5 per cent. Formerly, this tallow was 
frequently used for the making of oleo oil and for mixing with 
lard. Under the new regulations, it may still be used for the 
former product if suitable, but it cannot be mixed with pure 
lard unless the fact is plainly stated on the label. 

15. Tongue. — The tongue is always removed before the 
head is used for the other by-products. As this is one of the 
high-priced by-products of the animal, it is always handled 
to produce the best results in the way of weight, appear- 
ance, etc. Tongues are frequently sold in the fresh state; 
they are also, after the necessary preparation, sold in a pickled 
condition. 

After a period of curing in pickle, the tongues are often 
smoked after the manner of other smoked products and sold 
as smoked tongues. Differing from most of the by-products, 
the market demand for beef tongues is such that they are 
never tanked as surplus. 

16. Liver. — The liver taken from the bullock has the gall 
bag removed and is then washed, hung on hooks to drain 
and chill thoroughly, and sold in the fresh state. Where a 
surplus of livers are obtained, they are tanked for fertilizer 
material, or tankage that will analyze about 15 per cent, 
ammonia and no bone phosphate. Livers when cooked yield 
no tallow; when tanked and rendered with tallow material, 
they always discolor the resulting tallow. 

392—2 



12 PACKING-HOUSE INDUSTRIES, PART 1 

17. Heart. — ^After removal, the heart is cut lengthwise 
to a slight extent to allow the contained blood to escape from 
the interior. It is then washed in cold water and when 
thoroughly chilled is used for canning, mixed with other meat, 
for pickled goods similar to pigs' feet, for sausage, and very 
largely for the manufacture of beef extract. These processes 
will be described later. Hearts are also sold in the fresh state 
for food. 

18. Tail. — The tail is chilled after removal from the 
bullock and is either sold fresh or utilized in the making of 
canned soups. At times the tails are chilled or frozen and ex- 
ported. As they contain a large amount of gelatinous matter, 
they cannot be used for beef extract with any degree of success. 
Tails and all surplus of packing-house by-products when 
beyond the proper condition for food, ultimately find their 
way to the fertilizer tank. 

19. Tripe. — In making tripe, the first stomach, or paunch, 
of the bullock, containing the undigested food, is utilized. 
This undigested food is removed and utilized for the making 
of strawboard. To illustrate the progress in the utilization of 
the various wastes of the packing house, it is not many years 
since the packers paid for having paunch manure hauled away 
from the premises. Later, it was run through large rollers, to 
remove all juices and moisture possible and then mixed with 
coal and burned as fuel. At the present time practically the 
entire output is utilized for the manufacture of strawboard, as 
just stated. The fertilizing value of this paunch manure is 
very slight, as it contains when dried only 2 per cent, of 
ammonia; its low specific gravity and bulkiness make it 
undesirable for fertilizer mixtures. 

The paunch itself is washed in ice-cold water and all adhering 
fat is trimmed off. This fat when rendered makes a hard 
tallow having a titer of about 44° C, and a greenish-yellow 
color. 

Following the operation of opening and cleaning the tripe 
on the umbrella washer, the' old method of handling consisted 
of placing a quantity of the tripe in a tub where it was scalded 



PACKING-HOUSE INDUSTRIES, PART 1 13 

for a certain length of time, then transferred from the tub to a 
table where the inner or mucous lining was removed by scraping 
with bell scrapers and knives. This operation required con- 
siderable labor and extra handling of the product, and the 
quality of the product was not uniformly satisfactory. 

These objectionable features are overcome by a machine in 
which the scalding and scraping of the beef tripe is accom- 
plished simultaneously. The tripe, after being washed in 
the imibrella washer is placed in the cylinder of the machine 
with a certain amount of water. The machine is then started 
and the water gradually heated to a temperature of 140° F. 
As the scalding progresses, there is sufficient agitation and 
scraping by the machine to remove mechanically the tissues 
that were formerly scraped off by hand. 

This operation requires about 30 minutes and when it is 
completed the tripe is removed from the machine and placed 
in vats, where it is cooked for about 4 hours. It is then removed 
to tables where it is finished by trimming the edges, removing 
the thin outer covering and any remaining excess fat. 

The product is then chilled, either by being placed in ice 
water or hung in a refrigerator room for a few hours. It is 
then packed in barrels or kegs and vinegar is poured over it 
which tests 4| per cent, acetic acid or 45 grain. After standing 
open for 8 to 10 hours, the vinegar in the barrels is brought up 
to the original strength by adding 90 grain stock, care being 
taken that the tripe is completely immersed. The barrels are 
then coopered for shipment. 

20. Sweetbreads. — The sweetbread is the thymus gland 
of the animal and is characteristic of comparatively young 
animals. It has been found that cattle which have been 
fattened in feed lots yield much larger sweetbreads than Western 
or range cattle, being undeveloped in the latter because of 
their mode of living. In older cattle it practically disappears 
or becomes so shriveled in size as to be of no value. The 
weight of the full-sized sweetbread averages about J pound. 
Sweetbreads are always sold in the fresh condition and. con- 
stitute a very perishable product. 



14 PACKING-HOUSE INDUSTRIES, PART 1 

21. Beef Gall. — The beef gall, known in pharmacy as 
fel bovis, is frequently manufactured into inspissated ox gall. 
For this purpose the gall bladder is slit and the slimy, greenish 
gall is strained to remove the valuable gall stones. Although 
the yield of gall stones may amount to only a few ounces per 
month even in a large establishment, their sale price, which has 
reached the figure of $450 per pound, warrants their recovery. 
The stones are disposed of almost entirely to the Oriental 
races, who believe that they have considerable medicinal value. 

The gall itself is collected and evax3orated in an ordinary 
steam- jacketed kettle until a thick skin forms on top of the 
liquor. The original bulk is reduced about three-fourths 
when it is poured into shallow sheet-iron pans about 1 J inches 
high, 30 inches long, and 20 inches wide. At a temperature 
of 212° F., it is evaporated to dryness and kept in the drying 
room until wanted for grinding. As this material is very 
hygroscopic, this precaution is very essential. 

The grinding, or powdering, is accomplished in a specially 
constructed mill which grinds out of contact with the atmos- 
phere. Any machine that fills this condition is suitable for 
this purpose. The hard and brittle dried gall is removed 
from the pans only when wanted for immediate grinding. 
When sufficiently fine the gall is removed from the mill and at 
once placed in tin cans, which are immediately sealed air-tight 
by soldering. 

The inspissated ox gall is used to a considerable extent for 
medicinal purposes. The liquid gall is employed in the manu- 
facture of special soap for washing goods the dyes of which are 
loosely fixed. The liquid article is also used to a limited extent 
in fixing the dyes and colors of textile fabrics and carpets. 

22. Feet. — In the packing house, the foot is that part of 
the leg from the knee joint to the hoof. After removal the 
feet are stripped of the sinew lying along the shin bone. The 
sinews are in most packing houses salted down and kept in 
this condition until sold to the glue manufacturer. They may 
be cooked by themselves in the packing house, where they are 
resolved into glue liquor yielding about 20 per cent, dry glue, 



PACKING-HOUSE INDUSTRIES, PART 1 15 

5 per cent, neatsfoot oil, and from 3 to 5 per cent, dry tankage 
(not including the large bones of the feet) . 

The feet are next passed to the bone sawyer, who removes 
the knee joint and the foot proper with the attached hoof, 
in both cuts exposing the marrow at the ends of the shin bone. 
The feet are then placed in boiling water for 15 minutes, after 
which they are removed, and the hoofs forced off by a machine 
known as a hoof puller, leaving them in condition to be boiled 
for oil, glue liquor, and bones. The hoofs are then either 
dried, to be sold in this condition, or made into hoof meal, 
which is described later. 

The feet are put into open vats, washed free from blood, 
dirt, etc., and are then covered with clean water and cooked 
with live steam for about 10 hours, or until the bones fall 
apart and the oil separates. The glue liquor formed is cared 
for by the glue department, when in connection with the 
packing house, or it may be concentrated to a jelly and sold 
in this condition to the glue manufacturer. The bones washed 
free from adhering meaty matter are dried in this condition as 
raw bone, or they may be ground into raw-bone meal, as will 
be described further on. The ends of the sawed shin bones are 
boiled together with the feet, as they yield the same products. 
These ends are known as knuckles, and are utilized in the 
manufacture of bone black, as they are particularly adapted 
for this purpose. 

23. The tankage, or refuse, from the boiled feet is gen- 
erally recooked for several hours in order to obtain a fiuther 
yield of oil. A set of four feet gives approximately J pound 
of dried, high-grade tankage. The oil that exudes from the 
feet in boiling is neatsfoot oil. This oil is collected from the 
vat, freed roughly from water and scrap by settling, and then 
placed in an open iron tank and heated to 220° F., to drive off 
all moisture contained in it. While hot, the oil is passed either 
through cotton-flannel bags or, where there are large quantities, 
through a filter press, to remove fine scrap, hair, and other 
extraneous impurities. The oil when cool is ready for sale 
purposes as pure neatsfoot oil, or it may be further manipu- 



16 PACKING-HOUSE INDUSTRIES, PART 1 

lated, being made into neatsfoot, stearin, and winter-pressed 
neatsfoot oil. The latter process will be described later. 

The sawed shin bones are also boiled in open vats with live 
steam to prepare them for cutlery bones. The marrow of 
these bones also produces neatsfoot oil, which is mixed with 
that obtained from the knuckle bones of the feet. The refuse 
from the meaty matter of the bones is sent to the pressure tanks 
to be further rendered with tallow material for any remaining 
fatty matter. The bones destined for cutlery purposes are 
cooked 5 or 6 hours at a temperature not exceeding 210° F., 
in order to retain as much of the gelatinous matter as possible, 
thereby keeping the strength of the bone more or less intact. 
It is important not to overcook these, as by so doing their 
value is reduced to that of raw bone. In proper condition 
after cooking and drying, these bones are worth from $50 to 
$80 per ton. The cooked bones, freed from oil and tankage, 
are dried on racks at a moderate temperattu-e, about 70° F., 
and are ready for shipment. 

The open tanks in which bones for cutlery purposes, etc. 
are boiled should be provided with a false bottom, either 
perforated or slatted, under which steam pipes are placed. 
Otherwise, any bones lying directly against the live-steam 
pipes are liable to be discolored or overcooked, conditions 
that should always be avoided. 

Where these shin bones are not handled in this manner, if 
not desired for fancy bones, the whole shin and foot, except 
the hoof, is boiled together for the production of neatsfoot oil 
and raw bone, the tankage, as usual, being incidental. Raw 
bones of this description furnish a most excellent raw material 
for glue and gelatine. 

24. Casings. — Casings are products made from the 
intestines of cattle, sheep, and hogs, primarily, however from 
cattle. Their systematic treatment results in a product as clean 
and sterile as possible and when stuffed with chopped meat and 
spices constitute the sausage of commerce. Beef casings 
include the intestines, namely, rounds, middles, and bungs, 
and also the weasand and bladder. The bung is the end of 



PACKING-HOUSE INDUSTRIES, PART 1 17 

the large intestine which is cut off a length which varies from 
4 to 8 feet, depending on the size of the cattle. In the center 
of this intestine should come the opening where the small 
intestine connects with the large. Beef middles are the large 
intestines of the bullock and vary in length from 20 to 38 feet. 
The middle lies between and is connected with the bung gut 
and the round intestine. The round gut is the long intestine 
of the bullock and varies in length from 100 to 140 feet. These 
intestines lie connected with and surrounded by a mass of fat, 
constituting a heavy apron-like mass called the rufHe. 

In preparing the casings the round is first removed, then the 
middle, and finally the bung gut. These are first scraped free 
from fat either by hand or by the fatting machine, as the fat 
is of more value than the intestine itself. After fatting, the 
intestine is placed in cold water and turned inside out so that 
the inner slimy membrane may be removed. Since it is only the 
muscular portion of the intestine that is of value as the casing, 
it is essential that the cleaning process be carefully followed. 

After cleaning, the intestines are measured into sets, the 
rounds of approximately 110 feet, and the middles of 62 feet. 
These are then salted, piled on trucks to drain, and finally 
packed in fine salt in tierces preparatory for shipment. The 
rounds will measure now about 100 feet to the set and the 
middles about 57 feet. The bungs are handled exactly as ex- 
plained, except that no attempt is made to arrange them in sets. 

The weasand is the gullet, or lining of the throat, of the 
bullock and is a tough, translucent membrane. It is surrounded 
by or covered with a layer of soft, dark meat, which is stripped 
off and utilized in the manufacture of sausage. The weasands 
are then blown up with air, tied tightly, and hung up to dry, 
at a temperature of about 115° F. Narrow weasands are those 
which while drying have a weight of about 4 pounds hung on 
the end, drawing them out and making them narrower. These 
are blown less full of air than the regular weasands. When dry 
they are taken down, the ends cut off and the weasands 
bundled for shipment. 

The bladder is freed from urine, washed, and trimmed free 
from adhering fat, the latter being utilized for tallow. The 



18 PACKING-HOUSE INDUSTRIES, PART 1 

bladder is then blown to its fullest extent with air, and a string 
is tied around its neck while in this condition. It is dried at 
the air temperature, the neck cut off, flattened out, and sold 
in bunches of dozens. Bladders are used for the packing of 
putty. In England and continental countries they are some- 
times used for the packing of lard and for various industrial 
purposes. 

25. Fat. — Three classes of fat are obtained from the 
bullock, namely: oleo fat, edible tallow, and inedible tallow, 
which are further subdivided into several grades. 

There are three grades of oleo fat, or more commonly, oleo 
stock, which are as follows: No. 1, or neutral; No. 2, and No. 3. 
The No. 1 constitutes the highest grade and is practically free 
from taste and odor. The No. 2 stock is slightly darker in 
color, has a distinct suety odor, and is not as sweet as the 
preceding grade. The No. 3 stock is much darker in color, 
has a stronger odor and cooked flavor, and is not as sweet as 
grade No. 2. These three grades are rendered, as will be 
described later, from the abdominal or caul fat, the ruffle fat, 
the kidney fat, the cod fat, the fat from the top part of the 
heart, and others of lesser importance, all being used in the 
manufacture of oleo oils and oleo stearin. The average bul- 
lock will yield from 60 to 75 pounds of this fat. 

The second class of fat known as edible tallow is prepared 
from fat essentially as clean and wholesome as that used in 
preparing oleo fats, the only difference being that there are 
small particles of bone and meat attached to the fat. For this 
reason, it is necessary to render it in closed tanks under steam 
pressure whereas the oleo stocks are rendered in open kettles 
at low temperatures. Edible tallow is used as cooking fat 
and in the preparation of compounds with vegetable oils. 

It is customary to prepare three grades of inedible fat, which 
comprise the third class of beef fats, as follows: No. 1 or extra 
prime; No. 2, and No. 3. Extra-prime tallow is light in color 
and low in free, fatty acid, and is used in the manufacture of 
lubricating oils and soaps. No. 2 tallow has a darker color 
and is higher in fatty acid and is used exclusively in the manu- 



PACKING-HOUSE INDUSTRIES, PART 1 19 

facture of soap. No. 3 tallow comprises the lowest grade of 
inedible fat, being dark in color and high in fatty acid. It is 
used in the preparation of the cheapest grades of laundry soap. 
All fats derived from the direct slaughtering are known in 
the packing house as killing fats, to distinguish them from the 
cutting fats derived from the cutting up and trimming of the 
chilled dressed beef for the various cuts. 

26, Horns and Horn Piths. — Among the important 
by-products of the bullock are the horns. The constantly grow- 
ing practice of dehorning has caused the supply to diminish from 
year to year, and good horns are becoming scarcer each year. 
In spite of this fact, the value of horns has not been increased 
to any considerable extent owing to the fact that manufacturers 
use celluloid and similar compositions as substitutes. 

27, The horns on the cattle heads are sawed ofif close to 
the skull after slaughter. To separate the enclosed pith in the 
horn, it is merely necessary to cook the whole at 160° to 170° F. 
for 30 minutes. The hot water is then replaced by cold water 
to cool the horns and make their handling easier. A heavy 
stroke of the horn on iron, or vice versa, will cause the pith to 
fly out. It is very important that horns should not be over- 
cooked, as this will cause them to turn yellow and become 
brittle, thereby seriously damaging them. If, however, they 
are not sufficiently cooked, the pith cannot be removed without 
great difficulty. In this case, the horns must be reheated in 
the water until the proper condition for the removal of the 
pith is obtained. 

After the pith is separated from the horns, the latter are 
sorted into various grades — steer, cow, bull, stags, stimips, 
and useless horns. Steer horns are the most valuable, and 
have a smooth surface both on the outside and on the inside. 
This is a convenient practical test for distinguishing large cow 
horns from steer horns. The weight of steer horns is small 
considering the size, varying from 40 to 100 pounds per hundred 
pieces. They are classed as No. 1 horns. All steer horns 
averaging below 40 pounds per hundred, and cows, bulls, stags, 
and stumps are classed by the manufacturers as No. 2 horns. 



20 PACKING-HOUSE INDUSTRIES, PART 1 

Stump horns are those of all grades from which the tip is absent 
or badly damaged. Stag horns are of a rough nature, weighing 
about 2 pounds each. Useless horns include all misshapen, 
overgrown, or irregular horns. 

Horns will lose in drying about 12 per cent, of their original 
weight. They are stored in a cool place to prevent them from 
becoming too brittle. Horns are used for the manufacture of 
imitation tortoise shell, for combs, buttons, and similar articles, 
and for pipe-stem tips. The refuse horns, clippings, etc., are 
made into a fertilizer material called hoof meal 

28. Horn piths, after being knocked from the horn, are 
stripped of the skin covering them and then dried on the floor 
at a moderate temperature. The cleaner this product is and the 
freer from bloody tips, the higher price it will bring. Horn 
piths are used extensively for the manufacture of edible gelatines 
and also as an excellent raw material for the glue maker. 

29. Blood. — The blood from the bleeding bullock is con- 
ducted to a reservoir from which it is pumped to the cooking 
tank, or vat, in the fertilizer department. The liquid blood 
from the average beef is 40 pounds. 

30. Fertilizer Materials. — All material from the 
slaughtered bullock not wanted or not suitable for other 
purposes may be classed as fertilizer material. It includes 
lungs, pecks (the third stomach of the bullock), spleen, and 
refuse from the manipulation of the other by-products in the 
packing house. Fertilizer materials also include all animals or 
parts of animals that are found on examination to be diseased or 
unfit for food. This material when rendered, furnishes tankage, 
tallow, and tank water, the latter being the cooking water heavily 
impregnated with nitrogenous coippounds . Tank water is at the 
present time made into a fertilizing material by evaporation. 
This is known as concentrated tankage, or in the packing house 
as stick, the treatment of which will be described further on. 

The foregoing products, as mentioned before, may be and 
are subdivided in many cases, but this subject is best treated 
under the different classes of products, where they are discussed 
more fully. 



21 



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THK DISPOSITION OF A HOG IN THE PACKING HOUSE 

A Hog Yields 



Dressed Carcass 



Head 

! 



Lard Meat Tankage 



Manufactured Goods 
(Food Containers) 

I 



Fertilizer Material 



Glue Tankage Lard 



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OSal 



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Food Products 



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Heart Liver Leaf Lard Oil Lard Stearin 

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Fertilizer Food Pepsin Neutral Scrap 

Material Envelope Lard 



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L T 321 BB 392 414A 



PACKING-HOUSE INDUSTRIES, PART 1 21 



HOG PRODUCTS 

31. The dressed carcass of the hog is capable of many 
dispositions which depend on many conditions, notably the 
locality for which it is destined. The various methods of 
transforming the dressed hog into very numerous cuts, regu- 
lation and otherwise, is so complicated that personal observa- 
tion and practice is far more valuable than description. The 
resolution and disposition of the offal is more complex than 
that of the bullock. The offal from the hog, comparatively 
speaking, is of more value than that of the bullock, as the 
finished by-products of the former are much more remunera- 
tive to the packer than those from beef. 

32. The chart, Fig. 2, shows approximately the resolution 
of the hog into the most important packing-house products. 
The same is true here as with the chart of resolution of the 
bullock; that is, while showing the general result, many of the 
by-products may be still further divided when deemed profit- 
able. All these by-products are not manufactured in every 
establishment, but in the largest packing houses which are 
conducted on scientific principles with the aid of chemistry, 
these, together with many allied products, are manufactured 
in very large quantities. As many packing houses handle 
hogs only, the utilization of every product possible under the 
circumstances is a necessary factor in obtaining satisfactory 
financial results. The disposition of the offal in the packing 
house will be described in detail. 

The most important by-product, although not always con- 
sidered as a by-product, is lard. The subject is so important 
and the treatment and manufacture so varied that it will be 
treated under a separate heading. 

33. Head. — The head of the hog after removal at the 
time of slaughter is thoroughly washed in water so as to remove 
the blood and dirt. Several dispositions are made of this 
product. In all cases, the tongue is removed and treated by 
itself. The heads are scraped free from all hair and bristles, 
washed thoroughly clean in cold water, and chilled for 24 hours, 



22 PACKING-HOUSE INDUSTRIES, PART 1 

when they are ready for sale. At times, they are spHt in 
halves and pickled in strong brine for 2 weeks, when they are 
packed in barrels for shipment, mostly to tropical countries. 
When intended for lard purposes, the heads, after being 
cleaned and washed, are sent to the rendering tank with other 
suitable material and cooked for lard. 

Another use for the heads is the manufacture of headcheese 
in the sausage department. Here they are cooked in open 
vats until the flesh loosens when they are removed and the 
bones separated from the meat. This meat, together with the 
skin of the hog or similar glutinous matter for adhesive pur- 
poses, is made into a chopped mass with other materials, stuffed 
into cleaned hog stomachs, and then cooked in practically the 
same manner as sausages. This latter use is the most profit- 
able for the packer, as by it he obtains lard from the cooking 
of the heads, the meat for a profitable use, and the bones for 
fertilizer. 

34. Blood. — The blood from the slaughtered hog is con- 
ducted to a reservoir and treated the same as the blood from 
cattle, as will be described later. 

35. Food Products. — Broadly speaking food products 
include almost every part of the hog. With the exception of 
the gall, bones, and bristles, all parts may serve as edible 
products. Specifically, they will be treated here as the heart, 
liver, and leaf lard, the latter finding its most important use as 
neutral lard and as a component of oleomargarine, or butterine. 

36. Heart. — The heart finds its most important use in 
the production of sausages. It is frequently sold attached to 
the liver and lungs by a short piece of windpipe, the whole 
being technically termed the pluck. When not desired for these 
food purposes, it is sent to the tank and rendered for fat, the 
fleshy residue furnishing a fertilizer material rich in nitrogen. 

37. Liver. — In the United States, the liver of hogs finds 
restricted use as food, but in many foreign countries this is 
its only utilization. The fresh livers, preserved in a solution 
of salt, borax, and boracic acid, were largely sent abroad from 



PACKING-HOUSE INDUSTRIES, PART 1 23 

the packing centers, arriving at their destination many days 
afterwards in a condition hardly distinguishable from the liver 
freshly removed from the hog. Of late years, however, this 
disposition has been greatly restricted, owing to the passage 
of stringent laws in many foreign countries against the impor- 
tation of such meats packed with preservatives. 

Hog's liver is very serviceable as a component of piquant 
table sauces, although its use is limited. The livers are also 
cooked, dried, and then ground into a powder and used as a 
component of dog biscuit. This outlet is at times a very 
important factor in disposing of a surplus. When not desired 
for other purposes, the livers are cooked under pressure, when 
they yield only tankage and tank water. The tankage from 
livers when dried, contains about 14 per cent, of ammonia 
and furnishes a readily and easily available source of nitrogen 
in fertilizers. 

38, Leaf Lard. — Leaf lard when removed from the hog is 
chilled, as described later, when intended for the making of 
neutral lard. For sale purposes, it is hung from the middle 
of the piece on slanting pegs about 6 inches long, and 
allowed to chill in this condition. When removed, and with 
the skin side exposed, it presents a smooth, cone-like homo- 
geneous lump. 

39. Feet. — The feet after removal from the dressed hog, 
which has been chilled for about 48 hours, are sometimes sold 
in the fresh state after being thoroughly cleaned and freed 
from all hair and the homy toes. These toes, after being 
cooked under pressure to loosen the tissue so that they may be 
easily ground, are sent to the fertilizer tank. They furnish a 
fertilizing material containing about 19 per cent, of ammonia. 
This material is generally mixed with the ordinary tankage 
from hog offal to raise the grade in ammonia. The small 
projections on the back part of the feet, called the haws, 
corresponding to the dew claws on cattle, also have their homy 
covering removed, the material likewise furnishing fertilizer 
stock. The feet are also cleaned and cooked for 2 hours, after 
which they are split and placed in packages with vinegar and 



24 PACKING-HOUSE INDUSTRIES, PART 1 

spices. For this purpose, the feet are first subjected to pickling 
in a solution of salt and water for 2 or 3 weeks. They are 
sold as pickled pigs' feet. 

When not desired for food purposes the feet are cooked 
under pressure for lard and tankage. The lard obtained in 
this manner is of a very oily nature, consisting of a large 
per cent, of olein and very little stearin. It may be mixed in 
cool weather with ordinary lard, when its oily characteristics 
are not apparent. Pig's-foot lard furnishes on pressing into 
oil and stearin a very large yield of lard oil, and is very fre- 
quently utilized for this purpose. The yield of lard from feet 
is about 16 per cent. The most profitable use of pigs' feet for 
commercial products is for glue, which product is largely made 
in the Chicago packing houses. The front feet of the hog are 
usually employed for making pickled pigs' feet, while the hind 
feet are used for glue material and lard. 

40. Kidneys. — The kidneys are always removed from the 
slaughtered hog. The beef kidneys are always left with the 
dressed carcass, embedded in the kidney fat. Hog kidneys find 
extensive sale in the fresh state. The surplus goes to the render- 
ing tank. 

41, Hair and Bristles. — The hair and bristles of the hog 
furnish by-products of extensive utility. As the slaughtered 
hog emerges from the scalding tub, the bristles are selected 
from along the ridge of the back and the hams. They are 
chosen as to length and color, the black, brown, and white 
being kept separate. The hair and bristles are almost always 
sold by the packer to contracting firms at a certain price per 
hog. The season of the year, by virtue of the condition of the 
hair and bristles, largely influences this value. The contractor 
always takes care of the product, and furnishes all labor required 
for selecting, removing, curing, etc. The hair and bristles are 
spread in fields to dry, when they are packed with salt and 
brine in barrels and bags and sent to the brush manufacturers. 
Hair that is not suitable for this purpose is sold and made into 
a cheap grade of curled hair which is used for mattresses and 
for padding horse collars, cushions, etc. 



PACKING-HOUSE INDUSTRIES, PART 1 25 

Owing to the high percentage of nitrogen in hair, recent 
developments are toward the utiHzation of the cheap and 
ordinary hair for the production of nitrogen, in a soluble or 
available form, by dissolving it with acids or other suitable 
agents. 

42, Food Containers. — The same may be said of manu- 
factured goods of pork as was said of those of beef. From the 
hog they include sausage casings and bladders. The bladders 
are prepared by voiding and then soaking in cold water and 
brine for a day, when they are trimmed free from fat, distended 
with air to their fullest extent, and dried at a temperature of 
140° F. for 24 hours. After expelling the air and folding length- 
wise they are ready for use. The rough end, where they are 
tied shut, is cut before packing for shipment. 

Bladders of hogs find extensive use abroad for packing lard 
for sale purposes. They are sometimes colored and used for 
carnival purposes. Formerly bladders were largely employed 
for packing snuff. When parchmentized by means of dilute 
sulphuric acid, they are used for the covering of glass-stoppered 
jars and bottles. 

43. Casings. — Hog casings are classed as hog casings and 
hog bungs, the latter being the last 4 feet, or thereabouts, of 
the intestines. These, again, are graded according to length 
and condition. They are thoroughly cleansed inside and out 
and salted to preserve them, as is done with the beef casings. 
There is a marked distinction between the texture and appear- 
ance of the hog bung and the beef bung. The former is of a 
close, compact, and solid texture, with a white, opaque appear- 
ance. The beef bung is of a fibrous, heavily veined structure, 
and is of a yellowish, transparent or translucent appearance. 
The hog bung is almost universally employed for liver sausages, 
while that of the bullock is used for bologna sausages. 

Hog casings are made from the small intestines of the hog. 
The preparation of these differs from the manner of preparing 
the corresponding beef intestines. They are allowed to ferment 
for a day in warm brine, to loosen the attached mucous coating. 
This fermentation has been found by experience to be a neces- 



26 PACKING-HOUSE INDUSTRIES, PART 1 

sary procedure. It thoroughly and easily removes the mucous 
membrane and accompanying slime. Another day's soaking in 
moderately cold water prepares them for cleaning, which in 
small establishments is done by hand; in large ones, by 
machinery. The treatment of the intestines after cleaning is 
carried out the same as that of the beef casings, as has been 
described. This intestine of the hog varies in length from 
40 to 75 feet and, unlike that of the beef, is not fat nor embedded 
in fat, but simply attached to it. The yield of casings per hog 
is about J pound, and the use is for high-grade sausages. The 
refuse and useless intestines are tanked under pressiire for 
fertilizer material. 

44. Stomacli. — The stomach of the hog when voided, 
scraped, and cleaned furnishes an envelope for filling with 
sausage material such as headcheese. After cleaning, the 
stomachs are preserved in a strong solution of salt and water 
until used. 

The stomachs are also the source of a most important 
product — pepsin. Most packing houses do not make this 
finished product, but prepare the stomachs by cleaning them 
thoroughly and shipping them to the pepsin manufacturer in 
a solution of borax and boracic acid, or better, in a frozen con- 
dition. When stomachs are not used for the purposes just 
mentioned, they are cooked under pressure for fertilizer 
material, furnishing tankage similar to tripe from bullocks. 

45. Pancreas. — The pancreas, or sweetbread, furnishes 
the digestive ferment pancreatin. This product is made only 
by some of the largest packers. In establishments of moderate 
size the pancreas is usually tanked with fertilizer material. 

46. Fat. — The fat of the hog suitable for lard material is 
cooked for the production of lard of various kinds. All fresh 
and clean fat of the hog in sound condition is suitable for this 
purpose. All fatty refuse material not suitable for lard is 
cooked under pressure, producing grease and fertilizer material. 
Such material is found in the refuse from cleaning intestines, 
in catch basins, etc. 



PACKING-HOUSE INDUSTRIES, PART 1 27 

47. Fertilizer Material. — The fertilizer material of the 
hog consists of all material that is not wanted or is not suitable 
for food or other purposes. Products that have become 
unsalable or have deteriorated are also made into this material 
and the accompanying grease recovered. During the operation 
of dressing the slaughtered hog, many parts become so soiled as 
to be unfit for meat or lard, and these, together with all meaty 
and fatty material, are sent to the fertilizer tank. Clotted 
blood, the spleen, rejected intestines, etc., also furnish this 
material. 

Hogs condemned by meat inspectors on account of disease 
or unsuitable condition at the time of slaughter are also sent, 
viscera and all, to the fertilizer tank and rendered into grease 
and tankage. The water in which all meaty or nitrogenous 
animal matter is cooked under pressure is known as tank water, 
with the characteristics previously described. 

The products of the hog mentioned are the principal primary 
ones. As with beef products, these may be still further 
resolved. For example, lard and grease are made into lard oils 
and stearins. This subject will be treated later. 



CALF PRODUCTS 

48. When possible, calf products are disposed of in a 
manner analogous to those of beef. But the by-products of 
the calf are very limited, as about two-thirds of the live weight 
is disposed of as dressed meat. Calves are almost always sold 
with the skin, or hide, attached to the carcass. 

The viscera and internal organs of the calf, together with the 
legs and head, form the by-products. From the entrails and 
fat are produced a small quantity of tallow and tankage. No 
sausage casings are made from the entrails of calves, as 
their tender condition renders them entirely unsuitable for 
handling. 

The feet yield a small quantity of neatsfoot oil and when 
utilized for glue furnish a rich material for gelatine. A very 
limited demand exists at times for the cleaned feet in the fresh 
state, for edible purposes. 

392—3 



28 PACKING-HOUSE INDUSTRIES, PART 1 

The heads are sometimes cleaned, scalded, and prepared for 
food purposes. Where this is not done, they are tanked with 
the fertilizer material. They also furnish a serviceable glue 
liquor. 

The tongue is always removed from the head and is either 
sold in the fresh state or cured and sent to the canning depart- 
ment. 

Calf sweetbreads always find a ready sale as a table delicacy 
and bring very high prices. The brains are frequently removed 
from the heads and also sold as delicacies. 

The blood and worthless offal are made into the usual 
fertilizers. 

The heart, liver, and lungs attached to a piece of the wind- 
pipe, together known as the pluck, are always sold in the fresh 
state for food purposes. 

Unborn calves, known technically as slunks, are skinned 
when the hide is covered with hair. The rest is made into 
fertilizer. 

SHEEP PRODUCTS 

49. In slaughtering sheep, the usual method is first to cut 
the animal's throat, severing the jugular vein, and then to 
break its neck by bending its head back sharply. After the 
slaughtered sheep is dressed, the warm abdominal fat — the 
thin, apron-like sheet known as the caul — is wrapped around 
the carcass, encircling the hind quarters as much as possible. 
The kidneys attached to the body are pulled through a slit 
made in the warm fat, and the carcass allowed to chill in this 
condition. 

50. The offal of sheep is not so diversified as that of the 
hog or bullock, and is not subdivided to any considerable 
extent. The intestines are utilized in the manufacture of 
sausage casings, in the same manner as those of the hog and 
bullock, and in addition they are used in preparing tennis and 
musical strings, and surgical sutures. 

The hearts are used for the making of sausages, a large 
number, however, being sold in the fresh state. 



PACKING-HOUSE INDUSTRIES, PART 1 29 

The livers formerly found a large sale as calf livers. They 
are now sold under their proper designation. A distinguishing 
characteristic most frequently present in sheep liver is the occur- 
rence of hard limips, or cysts, scattered throughout the organ. 
These are never present in the liver of the calf. The livers 
that cannot be sold in the fresh state are tanked for fertilizer. 

The lungs are always tanked for fertilizer, when not sold as 
sheep pluck, this being the heart, liver, and lungs attached to a 
piece of the windpipe. 

The heads are either tanked under pressure or boiled in 
open vats for the production of mutton tallow, when in quantity. 
In the latter case, the residue remaining in the vats is further 
cooked in the pressure tanks, as a considerable quantity of 
tallow always remains in the material after this mild cooking. 
The heads are otherwise cooked with the rest of the fertilizer 
material of the establishment for tallow and tankage. 

The tongues are always removed from the head, and find 
their outlet as pickled lambs' tongues. Frequently, they are 
canned under the same name. 

The feet when cooked by themselves yield a dark-red oil, 
analogous to No. 1 neatsfoot oil. A test made on sheep feet 
for oil and tankage gave 4.54 per cent, of oil and 24 per cent, 
of dry tankage of low grade. Unless a large quantity of 
material of this nature is always on hand, the feet are cooked 
with other fertilizer material. 

Lamb fries is the trade name given to the testicles of sheep. 
They are sold in the fresh state under this name. 

The paunches emptied of manure are utilized for fertilizer 
material, as is also all other offal not otherwise used. 

The pelts of sheep are removed after slaughter. These are 
either disposed of fresh or made into packs with salt sprinkled 
between each skin for the purpose of curing them. In the 
largest packing houses, the wool is pulled from the pelt in a 
department known as the wool-pulling house. Here the pelts 
are treated with a depilatory which after a period loosens 
the wool from the skin and allows of easy removal. In the 
greater number of establishments, however, the pelts are sold 
as before mentioned. 



30 PACKING-HOUSE INDUSTRIES, PART 1 

Spring lambs are always sold with the pluck attached to the 
carcass and with the skin, or pelt, left on. 

Unborn lambs, if provided with wool, are skinned and the 
remainder is cooked for fertilizer. The skin of unborn lambs 
furnishes a most excellent material for the manufacture of 
parchment or vellum. 

The tallow obtained from sheep product is described further 
on. 

GOATS 

51. The slaughtering of goats is carried out in the same 
manner as that of sheep, as is also the dressing of the carcass. 
Their by-products so far as possible are handled like those of 
sheep. While in the aggregate a great many goats are annually 
slaughtered for food, their number is not as yet of sufficient 
importance in any one establishment to classify their by-prod- 
ucts under their own nomenclature. The carcasses of goats 
dressed like sheep were formerly sold in the trade as mutton. 



PROCESSES FOR THE MANUFACTURE OF LARD 

52. Lard is the rendered fat of the hog. The several 
grades of lard produced by the packing houses are made by 
quite different processes and the care of operating depends on 
the grade of lard, although careful attention to details is 
always of the utmost importance. 

The cheapest grade is steam-rendered lard; that is, the lard 
extracted from the stock by the direct contact of steam under 
pressure. Kettle-rendered lard is lard extracted in kettles 
heated externally, and is the highest grade of household lard. 
Neutral lard is made by a more complex process. 

The importance and value of this product are so great con- 
stituting as it does the largest by-product of the hog-killing 
branch of the business, that the methods of production will be 
given in detail. Many small points, while seemingly of little 
moment, are of the utmost importance in the treatment of 
this material. The production of a high-grade article by 



PACKING-HOUSE INDUSTRIES, PART 1 31 

proper cooking and handling is not only economical and 
advantageous, but it also obviates the too frequent after- 
treatment necessary to make a marketable lard. 



STEAM-REKDERED LARD 

53. Rendering Tank. — A modern rendering tank is 
shown in Fig. 3. The body d, the top di, and the conical 
bottom d-i, are made 
of steel or iron, riv- 
eted. The head a of 
the manhole is held in 
place by the clamp h 
and nut n. The pipe h 
is the exhaust leading 
to the condenser. 
The steam gauge k in- 
dicates the pressure in 
the tank. Steam is 
admittBd to the tank 
through the pipe /, the 
pressure being con- 
trolled by the valve m. 
The valves e are for 
drawing off the lard. 
The petcock / is for 
the escape of gases 
during cooking. The 
gate valve g is for the 
removal of cooked 
meat, etc. 

This tank is a 
marked improvement 
over the old-style tank, which is constructed with cone top and 
cone bottom. The apex of the bottom cone in such a tank, 
being always below the lowest of any draw-ofj cock, or valve, 
forms a receptacle in which the foul drainings from previous 
renderings collect, and is a most fruitful source of discolored 




Fig. 3 



32 PACKING-HOUSE INDUSTRIES, PART 1 

lard or other material unless great precautions are taken to 
remove this condensed liquid completely. In the modem con- 
struction, this great disadvantage is overcome, as may be 
readily seen. There are, however, a great many cone-bottomed 
tanks in use today in packing houses, but they are being 
replaced by tanks of the newer style. 

Many of the old-style rendering tanks have in them at the 
top of the cone or rounded bottom, false bottoms of perforated 
iron. The object of such a bottom is to keep the raw material 
from packing below the entry point of the steam, where it 
would escape cooking to a great extent. Another point with 
the false bottom is that it allows the water to percolate through 
it, retaining the solid material on top and level with the door, 
or gate, which, in this style tank, is about 15 inches square in 
the body of the cylindrical part of the tank. Through this 
gate the solid cooked material is withdrawn by means of long, 
bent forks. Naturally, there is considerable labor attached to 
this operation, which in the modem tank without a false bottom 
is entirely eliminated. The whole contents of the cooked tank 
is completely removed in a very few minutes by simply opening 
the large bottom valve g. This saving of time and labor during 
the busy seasons in the packing houses is of great impor- 
tance. Under the old system, serious delays were frequent, 
because the tanks were not cleansed and made ready for fresh 
material. 

54. The rendering tank is usually from 5 to 6 feet in 
diameter and from 14 to 16 feet high. The modem tanks are 
made of steel instead of iron and the cylindrical shell is made 
of two rings. The idea of modem qonstruction is to have as 
few seams as possible in the whole tank and to have the inside 
laps of the circular rings so arranged that they point down 
rather than up. In this way material that in a short time 
generates fatty acids that will rapidly corrode the seams, is 
prevented from lodging on the edge of each ring. 

A suitable combination of wood made impermeable to 
moisture or other material should be on the charging floor 
surrounding every tank, as by this means drippings of water 



PACKIXG-HOUSE INDUSTRIES, PART 1 33 

and washings from the floor mil be prevented from running 
down the sides of the tank. 

In the old-style tanks the bottom rested on a timber frame- 
work; this proved objectionable because it prevented access to 
the bottom plates and at the same time encouraged corrosion 
by keeping a wet surface constantly in contact with the iron. 
In modem construction the tank is suspended entirely free 
from the floors o, Fig. 3, except where supported on the lugs c. 
By this method, the external stirface of the tank is always 
visible for inspection and kept free from corrosion. 

55. Precautions for Safety of Tanks. — Rendering 
tanks in large cities are subject to the same regulations re- 
garding inspection as steami boilers. Even where municipal 
inspection is not obligator}', the packers have the tanks 
periodically tested and inspected. If the slightest flaw or 
weakness is detected, the tank is immediately put out of 
service until it is made thoroughh^ safe. 

The rendering tank is of such importance in the packing 
and rendering industries that the greatest care is taken in its 
construction. The life of the ordinar}' rendering tank is to a 
great extent dependent on the class of material cooked in it 
and the care it receives in handling. With good usage the 
average tank will last about 20 years. 

56. Operation of Steam Rendering for the Produc- 
tion of Prime Steam Lard. — The rendering tank must be 
thoroughly clean on the inside. When a new rendering tank 
is first put into service it is always used for cooking grease 
material in order to remove all rust, oil, dirt, and other 
extraneous matter incidental to its making. If this plan is 
not followed the lard coming from the new tank will alwa3^s be 
more or less dark and discolored and most likely "^^11 have an 
off flavor. This method of cleaning a new tank is always 
followed in the packing houses. 

Where the cone-bottom tank is used, great care should be 
taken to remove all the old tank water or other material from 
the apex of the cone. Clear water is run into the tank until 
it is about one-quarter full. The material is then dumped in, 



34 PACKING-HOUSE INDUSTRIES, PART 1 

care being taken, however, that the fat does not pack where it 
strikes inside the tank. Packing is a prolific cause of cold spots, 
and consequently of sour lard, and may be avoided by distrib- 
uting the material evenly over the interior of the tank with a 
long pole. 

The stock in the tank is thus washed while being loaded, as 
the filling is technically termed. To further this washing, a 
stream of cold water from a hose at the top of the tank is kept 
running over the material and, at the same time, in order to 
maintain the same level of water on the material, an equal 
amount of water is allowed to escape at the bottom. A great 
deal of blood from the material is in this way eliminated. 
The more washing lard material receives prior to the cooking, 
the better will be the quality and color of the lard produced. 

When the tank is about three-fourths full of stock ready for 
cooking, the flow of water is stopped both at the top and the 
bottom, and the head is put into the tank. This head, similar 
in shape to a manhole cover, is screwed down tight with a 
wrench that should not be longer than 18 inches. When the 
joint cannot be made tight with that leverage, the head should 
be removed and refitted with better packing. To force the 
head on with a longer leverage frequently results in a fracture 
of the mouthpiece or frame, and when steam is turned on 
in such a case, the tank is liable to burst and cause loss of 
life and property. 

57. When the tank is properly closed, steam is turned on. 
The steam is allowed to enter the tank under full pressiire, 
which is generally from 40 to 50 pounds. The safety valve is 
now tested to ascertain its free working. This valve should be 
so regulated that it will blow at the maximinn pressure used 
for cooking the material. The exhaust pipe on the top of the 
tank is kept wide open until the pressure gauge shows a pressure 
of a few pounds, when it is almost but not entirely closed, to 
allow the steam pressure to rise to the maximum. 

The pet cock /, Fig. 3, at the top of the tank is always kept 
open while cooking to allow the gases generated by the cooking 
material to escape. These gases are a mixture of hydrocarbons 



PACKING-HOUSE INDUSTRIES, PART 1 35 

and sulpho gases, of which hydrogen sulphide forms a large 
part. These gases, if confined while cooking the lard, would so 
impregnate it that the lard produced would be of an obnoxious 
flavor and unsalable as first-class product or standard lard. 

58. When the steam-pressure gauge shows a pressure of 
35 pounds the steam supply is partly shut off so that the 
incoming steam is balanced by that escaping from the petcock 
and the now partly closed exhaust pipe. In this way, the steady 
pressiu-e desired for cooking is maintained. It is very essential 
in cooking lard that a steady pressure be held with the steam, 
as in this way a uniform product can always be obtained. 

From 15,000 to 20,000 pounds of lard material, which will 
fill the average packing-house tank three-quarters full, should 
be allowed to cook at a pressure of 35 pounds for about 11 hours, 
the time being reckoned from the time that this pressure is 
obtained. With the tank only half or quarter full of stock to 
be cooked, a reduction of time of cooking and also of pressure 
must be made. Thus, with the tank quarter full, a pressure 
of 25 pounds for 9 hours will be sufficient, while with the tank 
half full a cooking of 10 hours with a pressure of 30 pounds will 
serve the purpose. The pressure employed, as well as the time 
of cooking, varies in individual packing houses, according to 
preferences and experience. For example, some prefer to 
render lard at a pressure of 40 pounds for 9 hours, which, in 
some cases, gives equally as good results. 

59. The object of cooking raw lard material under pres- 
sure is to cause complete breaking up of the membranous cells 
enclosing the fatty material, thus allowing the oily material 
to escape from its coverings, and to cook thoroughly the 
fleshy portions, so that what little of this remains in the 
rendered lard is in a large measure prevented from decom- 
posing. Incipient putrefaction of the raw material is thus pre- 
vented; hence, the great importance of rendering all material 
in as fresh a state as possible. 

One of the most vital points in making lard is to start with 
the material in the proper condition, that is, as clean as possible. 
This applies more forcibly to the lard material from the killing 



2>6 PACKING-HOUSE INDUSTRIES, PART 1 

of hogs than to the cuttings from chilled hogs that are made 
into customary cuts of hog product for the trade. The stock 
from freshly slaughtered hogs should be washed thoroughly so 
as to free it from blood and natiu-al filth. If this is not done 
the rendered lard will have a dark, brownish color and a dis- 
agreeable, strong, pungent odor. Such lard will not pass the 
usual inspection required for the sale of lard or the require- 
ments of the various boards of trade or chambers of commerce. 
(See Art. 92.) 

60. During the progress of cooking, the operator examines 
by feeling the outside surface of the tank, to ascertain whether 
or not the material inside is being heated equally. Should any 
part of the tank be cold, it shows that the stock is packed solid 
in that part and that the steam is merely cutting a channel for 
escape through it. This is technically known as a cold spot, 
and, unless remedied, gives rise to sour or putrid lard. The 
remedy consists in immediately shutting off the live steam and 
allowing the tank contents to settle for a short time. Then, 
from the valve in the back part of the tank, the water is drawn 
off until the lard appears. The valve is then closed and the 
steam again allowed to enter with full force. This procedure 
breaks up the compactness of the mass and disintegrates the 
material so that the steam then acts on each piece. The 
pressure is then regulated in the manner already described. 

It frequently happens that more material is placed in the 
tank for cooking than should be. In this case, while cooking, 
the tank becomes flushed, that is, the partly rendered lard 
with the steam and water is blown through both the petcock 
and the exhaust pipe, causing a serious loss of lard. This 
trouble can be remedied by shutting off the steam and drawing 
off from the tank by means of the back valve sufficient partly 
cooked material and water to reduce the level of the contents 
of the tank below the point where the lard is blown out. The 
back valve is then closed, the steam again applied, and the 
cooking proceeds in the regular way. 

The partly cooked lard which is drawn off is placed in the 
next tank of lard material to be cooked and the rendering of it 



PACKING-HOUSE INDUSTRIES, PART 1 37 

completed. Flushing is a very commori occurrence and is the 
cause of great losses in this branch of the business especially in 
the busy and crowded season when the tendency is to overload 
and crowd the tanks so as to take care of the large quantity of 
material. 

61. After the cooking is completed, the steam is shut off 
and the petcock is opened wide to allow the pressure to escape 
there as much as possible. At the same time the exhaust is 
closed, as are also the escape valves. The object of this is to 
prevent the rolling of the contents of the tank, and the conse- 
quent forcible projection of the rendered lard through these 
openings. If there is no sign of rolling, the blow-off and escape 
valves are opened a little at a time, observing, carefully that the 
contents do not roll. If the rolling occurs, these valves are 
shut and a short waiting period allowed until the cooked 
material has come to rest. After having blown off through the 
petcock about 30 minutes the steam is allowed to escape as 
rapidly as possible, the safety valve being opened to assist 
in this operation. The object is to reduce the pressure in the 
tank as rapidly as possible, so that no lard will blow away with 
the steam. 

After the pressure is gone, and not before, the head of the 
tank is loosened and allowed to hang in the manhole. The 
escape and blow-off, or exhaust, valves are then closed to 
prevent any induced suction from drawing the condensed liquid 
(made by condensation of the gases) from the exhaust pipe 
back into the lard. This is a most frequent source of the dis- 
coloration of an otherwise perfect lard, and is a point to be 
carefully guarded against. 

62. The rendered lard in the tank is allowed to rest for 
a period of several hours to enable the fine, cooked fiber dis- 
tributed throughout the lard to settle with the meaty material 
in the bottom of the tank. About 10 or 15 pounds of common 
salt is scattered on the surface of the lard, the object being to 
assist mechanically the fine scrap to settle. It also serves 
another purpose: The salt in passing through the lard comes 
in contact with the water, or moisture, still saturating it. A 



38 PACKING-HOUSE INDUSTRIES, PART 1 

union of the water and salt immediately takes place and forms 
brine, which, being so much heavier than lard, immediately 
sinks through it, thus eliminating to a large extent the moisture 
in the lard. The sprinkling of the salt materially shortens the 
time required for the necessary separation of the rendered lard 
from the water formed by the steam and the scrap and fine 
particles of meat scattered through it. The longer the time 
within limits allowed for settling, the better will be this separa- 
tion and the better will be the quality of the lard when drawn 
from the tank. 

63. When ready for drawing, or tapping, the lard from 
the tank, the water underlying the hot lard is withdrawn 
through the valve in the back of the tank near the bottom. 
This brings the lard down to the level of the valves e, Fig. 3, 
in the front of the tank. The level of the lard is lowered 
until on withdrawing from the front valves, the lard issues 
from them clear and free from scrap, when the valve in the 
back is shut, and the clear lard run from the tank to the usual 
receptacle. After all the rendered lard has been withdrawn, 
the lower gate, or drop bottom, of the tank is opened and the 
residue in the tank is allowed to run into the vat underneath 
the tank. The lard obtained by this process of cooking is 
prime steam lard, and constitutes the main output of lard from 
the packing house. The cooked material remaining in the 
vat is then prepared for fertilizer, the treatment of which will 
be described later. 

64. After the contents of the tank is dropped into the vat 
there is always more or less lard with it that rises to the surface 
of the tank water. It is not practicable or even advisable, to 
draw off the rendered lard from the tank completely, as there 
is always danger of drawing off some of the tank water with it. 
Unless lard is completely free from tank water, it will become 
sour, or decomposed, very quickly. As a matter of precaution, 
the flow of lard from the tanks is stopped when above the 
surface of the tank water inside, and whatever lard remains is 
allowed to mix with the tankage and tank water in the vat 
below, from which it is skimmed as it rises. This lard mixed 



PACKING-HOUSE INDUSTRIES, PART 1 39 

with water and some scrap is technically known as skimmings. 
These are returned to another tank of lard material when about 
to be cooked. 

65. Material from which prime steam lard is derived is 
made up of killing lard and cutting lard, so called in the packing 
house. The former consists of the fresh, fatty material from 
the slaughtering, such as the heads, gut fat, ham facings, 
various trimmings, etc., and yields from 40 to 45 per cent, of 
prime steam lard when rendered. Cutting lard consists of the 
trimmings, back fat, etc., obtained from the various parts of 
the chilled carcass. This almost clear fat when cooked for 
prime steam lard will yield from 70 to 75 per cent., depending 
on various conditions. 

From the average hog 8 pounds of lard is usually obtained 
from the killing fat and 22 pounds from the cutting fat, 
although the amount of back fat used with this material 
naturally influences the yield. The grease obtained from the 
average hog will be about J pound, or about 1 per cent, of the 
raw material. 

66. New Rendering Method. — The apparatus employed 
in the usual methods of rendering in the packing house has 
seen little change in form or improvement until recently. The 
sanitary authorities were nearly always in conflict with the 
Tenderer because the gaseous compounds unavoidably evolved 
in the rendering contaminated more or less the neighboring 
atmosphere. Within the last few years, a most excellent 
rendering system has been evolved that is destined in a very 
short period to supersede entirely the usual rendering apparatus 
in the small and medium-sized plants, and in all probability, 
those in the largest packing houses. This system is known as 
the Wannenwetsch combination sanitary rendering and drying 
system, and is so immeasurably superior to the old-fashioned 
rendering apparatus that a detailed description will be given. 

67. Fig. 4 illustrates a complete unit for rendering the 
fatty material, pressing the resulting tankage, or scrap, and 
drying the latter. This entire work is done in only one handling 



40 



PACKING-HOUSE INDUSTRIES, PART 1 



of the material and all operations are carried out in the same 
apparatus. 

The tank proper a, Fig. 4, is constructed very substantially, 
having heavy cast-iron heads in both the top and the bottom, 




Fig. 4 

in distinction to the usual riveted sectional head in the ordinary 
tank. The lower part of the tank b is made jacketed for steam 
pressure. The tank is provided in the interior with an agitator, 
which consists of a casting with blades that are actuated by 
the shaft and gearing c. A section of the agitator is shown at d. 



PACKING-HOUSE INDUSTRIES, PART 1 41 

68. Operation of Wannenwetscli System. — The 

material to be rendered is loaded in the usual manner, through 
a door in the top of the tank. The door is then closed and 
made tight, and steam for rendering is admitted into the tank 
at a pressure of 40 pounds. The cooking is continued for from 
2 to 4 hours, the time depending on the character and quantity 
of the material to be rendered. 

The agitator inside the tank is now set in motion for about 
15 minutes. This operation together with the cooking causes 
the destruction of the fat cells and disintegrates any bone 
present, thereby causing the fatty matter to be liberated. 
The cooking is continued for about 2 hours longer, when the 
agitator is again operated for further disintegration of the 
material. 

The steam is now shut off and the pressure is allowed to 
exhaust by means of a by-pass into the vapor line k, Fig. 4. 
The obnoxious gases (complex hydrocarbons, etc. ; see Art. 57) 
always generated in rendering are drawn through a spray of 
cold water into the vacuum condensing chamber, the non- 
condensable gases being conveyed to a gas-collecting chamber 
from which they are usually conducted to the furnace grates 
and burned. After all pressure is removed from the tank, the 
rendered lard, tallow, or grease is drawn off in the usual manner 
through the cocks g, g into settling tanks, or coolers. 

69. After all fatty material is drawn off, all lard cocks are 
closed, the 4-inch valve h leading to the air pump / and jet 
condenser is opened, and the tank a is exhausted through the 
pipe ^ to a 25-inch vacuum. The residue, consisting of tankage 
and tank water, remains in the tank for drying, contrary to the 
usual operation of dimiping the contents after rendering 

Steam is now turned into the jacketed lower part h of the 
tank, and the agitator is set in motion so as to prevent the 
material from baking or sticking to the heated surfaces and to 
assist the rapid evaporation of the moisture. By means of the 
testing valve m the material may be examined from time to 
time to ascertain its condition without any interruption of the 
operation. 



42 PACKING-HOUSE INDUSTRIES, PART 1 

When the tankage has become sufficiently dry, the door / is 
opened, and, with the agitator still operating, the material is 
discharged by its action in the condition of ground tankage. 
When ready for the next charge, the door / is again sealed, 
the agitator and the air pump stopped, and the steam to the 
jacket of the tank shut off. 

70. Advantages of New System. — By means of this 
unique system, the ordinary operations in the usual method of 
rendering and the separate pressing and drying of the tankage 
are eliminated together with the expensive tankage presses 
and driers. The heavy labor and expense always attached to 
these operations are saved and, in addition, tankage analyzing 
much higher in ammonia is obtained, owing to the tank water 
drying with the tankage at a low temperature. An increased 
yield of fatty material is obtained through the mechanical 
agitation while cooking, and consequently much less grease or 
fat is left with the tankage. The low operating expense and the 
wide adaptability of this system for rendering all classes of 
material, together with its obvious sanitary featiu-es, promise 
to replace rapidly the ordinary system of rendering offal. 



REFINED LARD 

71. The lard next in importance in the packing house is 
refined lard, which is made from the regular steam lard. 
Although the term refined lard in the past has referred to mix- 
tures of lard with tallow, cottonseed oil, etc., at the present 
time in the trade it refers exclusively to the pure and refined 
steam lard. The process of refining is very delicate and out- 
side of the packing house is unknown in all its details. 

By referring to Fig. 5, the method of operating may be 
followed. The iron tank A is provided with a cone bottom. 
The lard in the tank is heated by J-inch galvanized-iron pipes c 
running around the sides of the tank, the temperature being 
governed by the steam valve v. The blower pipe x extends 
from the blower, or air compressor Y, to the bottom of the 
tank cone, terminating in a circle about 2 feet in diameter. 
The blower pipe from the top of the tank is 2 inches in diameter. 



PACKING-HOUSE INDUSTRIES, PART 1 43 

The circle of pipe in the bottom of the tank is perforated with 
J-inch holes on the top, sides, and capped end for the purpose of 
distributing the air evenly through the lard, thereby agitating 
it violently when blowing. The cock m serves to remove water 
and settlings from the lard, and is consequently a very con- 
venient aid in cleaning the tank. 

The siphon d, held by the chain k, is attached to the feed- 
pipe ^ by a swivel joint inside the tank. The siphon may thus 
be raised and lowered at will, the lower position representing 
it when pmnping the last portions of material from the bleach- 
ing tank. The pump F withdraws the lard through the pipe e 
on opening the cock o and forces it into the filter press R, from 
which the bleached lard emerges and runs through the 2-inch 
pipe / into the agitator H for cooling, chilling, and drawing 
into the requisite packages. 

72. With the apparatus just described, the operation of 
bleaching the lard is conducted as follows : The lard is pumped 
into the tank A through the pipe b until within about 2 feet of 
the top. As the lard for this purpose is usually taken directly 
from the rendering tank, is always contains more or less mois- 
ture. The lard is heated to 170° F. and the air blower turned 
on the lard. This is continued for 15 or 20 minutes, when the 
moisture will be driven off. If the lard contains much moisture, 
a longer time will be required to drive it off. The practical 
test applied to ascertain the presence or absence of moisture is 
to fill an ordinary 4-ounce, oil-sample bottle with the hot lard 
and allow it to cool for a few minutes. If moisture is present, 
the lard will become very cloudy and appear thick; if absent, 
the clear, hot lard will remain clear for a long period. If the 
hot lard does not cloud in the bottle within 2 or 3 minutes, no 
moisture is present. 

73. Bleaching With Fullers' Earth. — The bleaching 
medium is now added to the hot lard. This, in packing houses, 
is always fullers' earth. The best temperature for bleaching 
lard is from 150° to 165° F., depending on the class of material 
under treatment. The quantity of fullers' earth, or clay, varies 
in the same way, from | to 3 per cent, being the usual amount 

392-^ 



44 PACKING-HOUSE INDUSTRIES, PART 1 

necessary to accomplish the bleach. Lard of ^ood grade will 
require approximately 1| per cent, to mc^ke it snow white. 

The necessary percentage of fullers' earth having been 
added while the lard is agitated, the pump is started a few 
minutes afterwards, the fullers' earth in the interval acting on 
the lard and absorbing the coloring matter. The lard and clay 
are pimiped into the filter press, the first runnings therefrom 
being returned to the bleaching tank, as they are usually not 
quite free from the fine fullers' earth. Until the filter-press 
cloths become filled and coated with the earth, the lard should 
be returned to the bleaching tank. The three-way cock g, 
Fig. 5, attached to the filter-press trough readily allows of this 
return by running from it through a movable pipe back to 
the tank. 

The thoroughness of the bleach is determined by holding in 
a water- white glass, the bleached lard to the light, when the 
natural yellowish tinge of lard is apparent. When the lard 
and the glass are of the same color, the bleach is perfected, no 
tinge of color appearing. The lard is then turned through the 
pipe / into the cooler and agitator //, where it is stirred and 
agitated mechanically until cooled to a thick, creamy consis- 
tency, so that it is barely able to flow or be drawn off through 
cocks or faucets. 

74. The longer within limits and the more the bleached 
lard is agitated, the whiter is its appearance in the drawn-off 
packages. The agitation continues until all the lard has been 
withdrawn from the agitator. After all the lard has been 
pimiped from the bleaching tank, the air blower is shut ofif 
from the tank and turned on to the filter press, so as to remove 
the lard held between the plates of the press. 

The air pressure forces out the lard, which is added to that 
already in the agitator. To obtain what lard is held by the 
fullers' earth on the filter-press cloths, the air is shut off from 
the press and steam is forced through the whole press. The 
lard issuing from the filter press under these conditions must 
not be allowed to mix with good lard; it is usually sent to the 
grease tank. The steam is continued on the press until all 



PACKING-HOUSE INDUSTRIES, PART 1 45 

grease matter has been steamed out. The air now replaces the 
steam and the blowing is continued until the cloths and press 
are dry. After removing the fullers' earth from the cloths by- 
scraping or shaking, the press is again ready for filtering. The 
cloths used for filtering are closely woven, strong drilling that 
is capable of withstanding great pressure. They are usually 
furnished by the filter-press manufacturers. 

75. The most important points in bleaching are the com- 
plete absence of all moisture and the proper high temperature 
— about 165° F. The former condition, however, must prevail 
or there cannot be a bleach. When fullers' earth is added to 
moist lards or oils, it immediately assimies a pasty condition, 
and when pumped with the lard into the filter press, it clogs 
the filter cloth very quickly with the pasty clay, rendering it 
absolutely air-tight. When this condition occurs, the whole 
operation from the blowing of the material must be started 
again to eliminate the moisture; but at best it is a precarious 
condition, as too long a contact between the moist clay and lard 
will impart an earthy taste to the latter, rendering it unsalable. 

76. Conditions for Satisfactory Bleaching. — If the 

temperature of the material is too low, the coloring matter will 
not be taken from it by the fullers' earth. As a rule, the lower 
the temperature at which the bleach is carried out, the better 
will be the resultant product. It is necessary, however, to 
have a temperature sufficiently high to cause the absorption of 
the coloring matter present. So far as has been ascertained, 
the action of fullers' earth in bleaching lard, oils, etc. is purely 
physical, no chemical reaction between the two taking place. 
The physical condition of the earth employed in bleaching 
greatly influences its efficacy. It has been demonstrated that 
two clays of the same chemical composition may act radically 
different in effecting a bleach. One would answer every require- 
ment in this direction, while the other gave no indication of 
bleaching power, thus demonstrating the fact that the chemical 
composition plays no part in this process. The fullers' earth 
used in the packing houses is tested in a comparative and 
practical way, as will be explained further on. 



46 



PACKING-HOUSE INDUSTRIES, PART 1 



77. Lard Coolers. — Many forms and varieties of coolers, 
or agitators, for lard are used. The upright open tank in 
which are revolving arms that work in conjunction with sta- 
tionary arms on a fixed central shaft, is much used. While 
this style of cooler will perform the work satisfactorily its 
chilling capacity is not sufficient for the large packing houses 
having daily outputs of carloads of refined lard. These 
agitators have a double shell through which cold water or 
brine circulates, thereby chilling and agitating the hot lard at 
the same time. 

Another form of chilling apparatus is a long, semicylindrical 
tank, or box, in which is fitted a revolving, horizontal screw 
that works in and out of the hot lard alternately, thus exposing 




Fig. 6 



it to the air. 
continually. 



This cooler sets in ice-cold water which circulates 
It is adapted only for small manufactiurers. 



78. Lard Roll. — The most modern and perhaps the most 
convenient and economical method of cooling bleached lard is 
by means of the lard roll, or cooling cylinder, shown in Fig. 6. 
These cylinders are made in all sizes and are well adapted for 
quick chilling. They are cast in one piece of cast iron and in 
the refinery are connected with a circulatory system of brine 
or ice water, thus keeping the surface of the roll constantly 
cooled. The lard flows on the top of the cylinder a, as it 
revolves, and by the time the lard reaches the attached scraper c 
it is chilled hard. The cooled lard falls into the trough b under- 



PACKING-HOUSE INDUSTRIES, PART 1 47 

neath and is removed therefrom by means of a pump or a 
spiral conveyer d adjacent to an agitator where the lumps are 
broken up. The lard is then filled into the various packages 
from this agitator. 

79. In some establishments two rolls are used : one, chilled 
by ice water, receives the hot lard; the other, chilled by 
refrigerated brine, finishes the chilling. Where large quantities 
of refined lard are made daily, the use of the lard roll is a neces- 
sary requisite for rapid working. These rolls revolve at a 
speed of about ten revolutions per minute and occupy a floor 
space of about 12 ft. X 6 ft. The cost of each ranges from $500 
upwards. 

A recent improvement on the lard roll consists in flowing 
the material onto the side of the roll, the arrangement of the 
scraper being such that the lard receives a much longer contact 
with the chilled surface of the roll. 



KETTLE-RENDERED LARD 

80. Kettle-rendered lard is an important product of the 
packing house, as it is the best grade made for the household 
trade. While this lard was formerly popularly supposed to be 
made from leaf lard alone, this was never true to any extent. 
The usual proportions of fat from which kettle-rendered lard 
is made are, approximately, one-third back fat and two-thirds 
leaf lard, though these proportions are varied at will. 

The lard material is filled into a steam-jacketed kettle 
which is constructed so as to withstand pressure. The back 
fat has the rind, or skin, removed and is put in and mixed with 
the leaf lard. A small amount of fluid rendered lard is put 
into the kettle before turning on the steam to assist the 
material in rendering. The material is cooked until the 
natural moisture of the fats has been eliminated, which requires 
about 3 hours for a 3,000-pound batch. The hot lard, freed 
from moisture, is quiet on the surface and free from rising 
steam bubbles. The steam pressure, as shown by the pressure 
gauge, should not exceed 10 pounds per square inch, which 



48 PACKING-HOUSE INDUSTRIES, PART 1 

gives sufficient heat to cook the lard fully in the time just 
stated. 

The cooked lard is allowed to remain in this kettle until all 
the fine scrap has settled; then it is either drawn directly off 
through strainers and muslin into packages or run into another 
settling tank where it remains until wanted for filling into 
packages. In order to get any lard remaining in it the scrap 
remaining in the kettle is sent to the steam-lard tanks for further 
rendering. 

Kettle-rendered lard that has been thoroughly cooked, if 
free from moisture and scrap, will keep for a long period, even 
under unfavorable circumstances. This lard, if properly made, 
does not require bleaching; but, if desired, it may be bleached 
in the usual manner with a small amount of fullers' earth. If 
the lard becomes burned, or if dark-colored material is used, 
bleaching is necessary to bring it to the required snowy white- 
ness. 

81. Where large quantities of kettle-rendered lard are 
made, recourse is had to apparatus similar to that shown in 
Fig. 7. This apparatus is the same in every way as when 
making neutral lard, except that the kettle D is steam- jacketed 
instead of being water-jacketed. The lard material is hashed 
into the kettle and cooked the required time. 

Kettle-rendered lard has a characteristic, distinctive, agree- 
able smell imparted to it by the method of cooking. Instead of 
rerendering the cooked scrap, it is often pressed in a lard press, 
to recover as much lard as possible from it. This course is fol- 
lowed in small establishments where leaf lard is made, such as 
butcher shops, etc., and where there are no pressure tanks for 
further rendering. The residue remaining from this pressing is 
known as cracklings from which the fertilizer material azotine 
is made. Cracklings are also used for making poultry food by 
mixing with ground bone. They always contain a very large 
percentage of fat. 



PACKING-HOUSE INDUSTRIES, PART 1 



49 



NEUTRAIi LARD 

82, Neutral lard differs radically from other lards both in 
its nature and manufacture and requires apparatus entirely 
different from that necessary for the production of the other 
kinds. This lard is made from leaf lard principally, but at 

times it is profit- 
able to make it 
from material other 
than this, which 
will be described 
later. 

83. Process 
of Manufactur- 
ing Neutral Lard . 

The method of pro- 





ducing neutral lard is car- 
ried out as follows: The 
hot leaf lard from the hog 
is hung, each piece sepa- 
rately, on flat sticks fitted 
into sections in the chill 
room, until the leaf has be- 
come thoroughly chilled, 
which requires from 24 
to 48 hours. The best 
temperature for this is just 
above the freezing point, 
about 33° F. The leaf 
lard is then removed to 
the place of manufacture, which is in a part of the estab- 
lishment remote from odors that might easily impart a 
taint to this susceptible material and thus render it useless 



Fig. 7 



50 PACKING-HOUSE INDUSTRIES, PART 1 

as neutral lard. The apparatus and its arrangement are shown 
in Fig. 7. 

The lard is introduced into the hasher B, which is driven by 
pulley a and revolves at a speed of about 600 revolutions a 
minute. The hasher is provided with a steam jacket through 
which live steam is constantly circulating during the period of 
hashing, or disintegration. The leaf lard is disintegrated into 
a plastic mass by the action of the revolving knives attached to 
the shaft of the pulley a, and falls through the spout 5 into the 
melting kettle Z). This kettle is water-jacketed; that is, the 
inside steel kettle is surrounded by another shell. In between 
is water, the temperature of which is regulated by live steam. 
The two kettles are not closed at the top, so no pressure or 
temperature above that of boiling water is possible. The 
plastic lard as it drops into the kettle is constantly stirred by 
means of the revolving arms fixed to the shaft c, which move 
at the rate of 35 revolutions a minute. The object of this 
agitation is to prevent the lard from becoming overheated in 
any one part by lying against the shell of the kettle. The 
temperature is gradually raised from the starting point to 
about 120° P., to overcome the chilling of the melting lard 
caused by the cold lard constantly entering the melting kettle. 
Only sufficient heat is given the water to keep the temperature 
rising about 1° in 5 minutes. 

84. It will require at least 40 minutes to fill the average 
kettle, which holds approximately 3,000 pounds of material. 
The kettle, filled to within 6 inches of the top, will be at a 
temperature approaching 126° P. The stirring is continued, 
keeping the temperature steady at this point for 15 minutes, 
more or less, when all the lard will be melted. The latter 
operation is materially assisted by breaking any unmelted 
lumps with the hands. In about 5 minutes more the fine 
melted scrap will be seen to collect rapidly at the top, when 
the operation is completed. The steam is tightly shut off, the 
paddles, or agitator, raised free from the surface of the lard by 
means of the chains m, and the melting mixture allowed to 
remain at rest for 15 minutes. The temperature by this time 



PACKING-HOUSE INDUSTRIES, PART 1 51 

will have risen to 130° or 135° F., which temperature must 
not be exceeded. 

The floating fine scrap from the leaf is then removed from 
the top, the last particles by a gauze skimmer. The removal of 
scrap is assisted by scattering about 6 or 7 pounds of fine salt 
over the surface of the lard. This also facilitates the removal 
of moisture (see Art. 62). The melted lard is now siphoned 
off by means of the pipe with a swivel joint attached to the 
side of the kettle; the outside end of this pipe is shown at e. 
The lard as it issues from e flows through a fine brass gauze 
sieve placed over the clarifying kettle F, to catch any floating 
scrap. This kettle is also water-jacketed. The neutral lard is 
allowed to remain in the clarifying kettle for 2 hours, when it is 
run through the siphon g into the settling kettle H from which, 
after remaining at least 4 hours, it is drawn into the tierces. 

85. Packing and Graining. — ^The lard must be held in 
the jacketed kettles at a temperature of not more than 130° F. 
When drawn into the tierces the lard is strained through cheese- 
cloth to catch any possible fine floating scrap. It should be 
filled in the tierces at this temperature and at once removed to 
the graining room which is kept at as nearly uniform tempera- 
ture as possible (between 55° and 60° F.). The 3-inch bungs in 
the sides of the tierces are removed when the tierces are placed 
on their sides in order to allow as much lard odor as possible to 
escape. 

After remaining undisturbed for 3 days, the lard will be 
found to have a grainy consistency. In other words, the 
stearin and olein of the lard have separated; the larger the 
grains of stearin are the choicer is the lard. When the lard is 
in this condition, the tierces may be removed at will; but if 
disturbed before this separation occurs, the lard will assume 
the uniform, smooth consistency of ordinary lard and be 
unsalable. The neutral lard in the required grainy condition 
is then finished and ready for shipment. 

86. Returning to the melting kettle: After all the clear 
lard has been removed, the fibrous, brownish residue is let out 
through the pipe and valve k into a receptacle below. This 



52 PACKING-HOUSE INDUSTRIES, PART 1 

residue, consisting of water, scrap, and more or less lard, is sent 
to the rendering tank in order to obtain as prime steam lard 
whatever has failed to be drawn into neutral lard. An analysis 
of the scrap removed from the top of the kettle was as follows : 

Per Cent. 

Moisture 3.70 

Fiber 28.91 

Lard 67.39 

Total 100.00 

87. Grades and Properties of Neutral Lard. — There 
are no chemical requirements for neutral lard. The only trade 
requirements are purely physical, consisting of condition, taste, 
and complete absence of any odor whatever. The taste must 
be bland and more or less milk-like. The condition, as before 
mentioned, must be a sharp and decided separation of the 
stearin from the olein. The color of neutral lard is always 
snow-white. The lard made from the leaf is known as choice. 
No. 1, or extra neutral. 

88. When the price is suitable and favorable conditions 
prevail, a neutral lard, known as No. 2 neutral, may be made 
from back fat and fresh ham fat. This material is freed from 
the accompanying rind, or skin, and treated in the same manner 
as the leaf lard with the exception of temperature. This 
material containing a much larger proportion of stearin must 
be melted at a higher temperature to obtain a fair yield of 
neutral lard. The melting of this class of material takes place 
at a temperature of 136° F., the temperature rising to 142° F. 
— the limit to which it should be carried. The further treat- 
ment of settling, etc. is the same as that described for regular 
neutral lard. 

89. Uses of Neutral Lards. — The principal use of neutral 
lard is for the making of oleomargarine, or butterine. As this 
lard is not fully cooked, but melted, its keeping qualities are 
very limited; hence, no attempts are made to cater to household 
trade. Neutral lard must always be kept in cold storage, or 
it will quickly become rancid. The yield that may be obtained 



PACKING-HOUSE INDUSTRIES, PART 1 53 

from average leaf lard is about 92 per cent, of neutral lard ; from 
the residue cooked under pressure a further percentage of steam 
lard is obtained. The approximate cost of an apparatus to mako 
neutral lard is about $1,500, more or less, and, together with 
that shown in Fig. 7, it consists of a few minor utensils such as 
trucks, strainers, etc. Neutral lard always brings a higher 
price than any other. 

STIFFENED LARDS 

90. In making lard for siunmer sale or for warm climates 
it must be made of such consistency that it will remain in a 
more or less solid condition. This does not in any way apply 
to prime steam or neutral lards but only to kettle-rendered 
lard and refined lard. 

91. Methods of Stiffening Lards. — The most rational 
method of stiffening lard consists in selecting the stock before 
rendering, by using for steam lard or other purposes the softer 
parts of the fats such as feet, and using only those parts which 
are naturally firm, on account of the greater amount of stearin 
contained in them, for the refined or kettle-rendered lard. 
While this method is practiced largely in establishments where 
such selection may easily be made, smaller packing houses are 
obliged to use another method. This consists in adding to the 
lard an amount of lard stearin not exceeding 5 per cent. Lard 
stearin added to lard to this extent is not an adulteration, as 
it is a natural constituent of the lard itself. 

92. The following are excerpts from rules regulating trans- 
actions in lard among members of the New York Produce 
Exchange, adopted at a meeting of the Lard Trade, held 
March 27, 1890, and amended July 1, 1921. 

Prime Steam Lard Standapd 
Rule 2. — Sec. A. Standard prime steam lard shall be solely the 
product of the trimmings and the fat part of the hog rendered in tanks 
by the direct appHcation of steam and without subsequent change in the 
grain or character by the use of agitators or other machinery, except as 
such change may unavoidably come from the transportation. It must 
have proper color, flavor, dryness, and soundness for keeping, and no 
material which has been salted must be included. All lard must be 



54 PACKING-HOUSE INDUSTRIES, PART 1 

rendered in conformity with the rules and regulations of the United States 
Depar>:ment of Agriculture. The name and location of the renderer, the 
date of packing, and the grade of lard, shall be plainly branded on each 
package at the time of packing. 

Sec. B. Prime steam lard of superior quality as to color, flavor, and 
body may be inspected as "Prime Steam Lard, Choice Quahty," and shall 
be deliverable on contracts for "Prime Steam Lard." 

Regular Trades 

Sec. B. In the absence of any special agreement, all lard sold on the 

spot or to arrive shall be understood to be the Standard quality of "Prime 

Steam Lard," and which is generally termed in future trades Contract 

Lard. 

Packing and Cooperage 

Rule 4. — Sec. A. Prime steam lard made between October 1 of any 
year and December 31 of the year following only shall be considered 
"Standard," and a good delivery on contracts maturing during that time. 

All lard to be classed as "Standard" shall be packed in new cooperage 
and made of well-seasoned white or burr oak free from objectionable sap. 

Sec. B. The dimensions of tierces shall be about as follows: 32 inches 
long with 21-inch head, or 33 inches long with 20|-inch head; staves to 
be chamfered at the head; staves f of an inch thick, head 1 inch thick 
in center and f at bevel; hoops hickory or white oak or other good wood, 
to be hooped not less than 11-16. 

Iron bound tierces shall be classed as Standard if made in compliance 
with the requirements of this rule as to heading and staves and hooped 
with not less than three (3) good hoops on each end, head hoops If -inch 
18-gauge, quarter hoop l|-inch 19-gauge, bilge hoops l|-inch 19-gauge. 

Standard Weight of Tierces and Tank 
Rule 5. — Tierces shall contain not less than 340 pounds lard nor more 
than 410 poimds. The "Standard" net weight of tierces of lard shall be 
375 pounds, and any variation therefrom, when delivered on future con- 
tracts, shall be settled for at the settling price of the 11 o'clock call on the 
day of delivery. The number of packages contracted for must be delivered, 
and all tierces must have weights and tares marked thereon. Tanks, in 
the absence of any special agreement, shall be understood to contain 
60,000 pounds net. Any variation therefrom exceeding five per cent. 
(5 per cent.) either buyer or seller may have the right of settling at the 
market price on date of delivery. 

Inspectors and Weighers 
Rule 6. — Sec. A. All inspectors and weighers of lard for delivery on 
sale or contract under the rules of the Exchange must be members thereof, 
and licensed by the Board of Managers, and must obligate themselves 
not to buy or sell on their own account any article they are licensed to 
inspect or weigh. 



PACKING-HOUSE INDUSTRIES, PART 1 55 

No certificate of lard, tallow, grease or animal product of any descrip- 
tion shall be considered proper unless worded in harmony with the rules 
and regulations of the U. S. Department of Agriculture. And all licensed 
inspectors' certificates shall state whether, upon evidence at hand, the said 
products came from a" U.S. Inspected Establishment " and " Uninspected 
Establishment" or "Origin not stated." Care should be taken not in any 
way to facilitate the passing into interstate or foreign commerce of edible 
meat food products from establishments not under U. S. Inspection. * * * 

Weight, Inspection, and Tares 

Rule 7. — Sec. A. The seller shall have the right to designate the 
weigher, but buyers shall have the right to designate an Inspector; either 
shall have the right to appeal to the Committee, as the case may be, 
whose decision shall be final and binding. 

Sec. B. To determine the tare on lard, four (4) per cent, of the number 
of packages shall be tested at the expense of the seller. The tare shall be 
ascertained by scraping the lard from the packages, and not by removal 
by dry heat or steam. The empty packages shall then be weighed and 
the lard replaced, and the weight of the refilled packages shall be the gross 
weight. 

Sec. C. In testing for weight and tares, packages which are evidently 
mismarked shall be excluded from the average. 

Sec. D. AU appeals from weight, inspection, and tares must be settled 
at the place of delivery unless otherwise agreed upon. 

Sec. E. Seller must give buyer timely notice to attend to inspection, 
weight, and tares. If buyer fails to attend to the same within a reasonable 
time, it shall be the duty of any two members of the Committee on Lard, 
upon such notice and failure, without fees, to appoint an inspector to 
sample the lard for delivery on that notice, and his inspection shall be 
final on that delivery. 

Lard Calls 

Rule 9. — Sec. A. There shall be, if required by the trade, two public 
calls of lard each day, except Saturdays, when there shall be only one call. 
The Committee on Lard shall fix the time when such calls shall be held. 
These calls shall be conducted by a person appointed by the Board of 
Managers or in his absence by a person to be selected by the majority of 
members present. 

At the last call prime steam lard in second-hand hardwood tierces, 
prompt delivery, will be called, if required, weighing and inspection to be 
paid by the buyer. 

The months shall be called in their respective order. No offer to buy 
or sell shall be entertained at a less difference than 1 cent per hundred 
pounds (100 pounds). 

The first offer to buy or sell at a price shall be accepted before subse- 
quent offers at same figures may be placed. Subsequent offers to sell at 
a lower or buy at a higher price shall vacate prior offers to seU at higher 



56 PACKING-HOUSE INDUSTRIES, PART 1 

or buy at lower prices. A transaction shall vacate all previous bids and 
offers, except as provided in Section B for transactions in stated quantities. 

Sec. B. Unless otherwise specified, all offers to buy or sell shall be 
understood to be in lots of 100 tierces or 37,500 pounds. Offers to buy or 
sell in larger quantities than above specified shall be in multiples thereof, 
and offers to buy or sell any part of the amount which may be named 
shall take precedence of stated quantities; but if stated quantities are 
offered or bid for, transactions in smaller parcels shall not vacate such 
offers to buy or sell, but the same shall be governed by the conditions of 
Section A of this rule. * * * * 

Rule 10. Either party to a contract, prior to or upon signing the same, 
shall have the right to call an original margin of $1 per tierce on lard, and a 
further margin may be called from time to time to the extent of any varia- 
tion in the market value from the contract price. 

Where no original margin has been deposited, calls may be made from 
time to time to the extent of fifteen (15) cents per one hundred pounds 
(100 pounds) above or below the market price of lard. * * * 
Method and Form of Contracts 

Rule 11. The seller and buyer shall in every case make out the 
confirmation slips on day of transaction, as per the following form: 

CONFIRMATION SLIP 

New York 19 

I (or we) hereby confirm sales (or purchases) made by me (or us) today, 
under the rules of the New York Produce Exchange and either party may 
at any time demand a contract in place hereof as provided by the by-laws 
in lieu of this slip, as follows: 

To, (or from) 



Amount ! Delivery 



Kind of Property 



Price 



(Signed) 

The following shall be the form of contract for lard sold for future 
delivery, which either party may at any time demand in lieu of confirma- 
tion slip: LARD CONTRACT 

New York 19 

In consideration of one dollar in hand paid, the receipt of which is hereby 
acknowledged, we have this day sold to (or bought from) 



PACKING-HOUSE INDUSTRIES, PART 1 57 

One Hundred Tierces of Prime Steam Lard, at cents p3r lb., 

deliverable at seller's (or buyer's) option. This contract is made in view 
of, and in all respects subject to, the By-Laws and Rules established by 
the New York Produce Exchange in force at this date. 



Signature , 



Appeal on Construction of Rules 
Rule 22. — Sec. A. Any party feeling himself aggrieved by the decision 
of the Committee on Lard, in the inteipretation of these rules, shall have 
the right to appeal to the Board of Managers of the Produce Exchange. 
Sec. B. No change shall be made in the rules by the Committee on 
Lard before submitting the same to a meeting of the Lard Trade, at which 
ten shall form a quorum. 

Inspection Rates 

Note.— At a meeting of the Lard Trade, held May 16th, 1892, the 
following were fixed as the minimum charges on lard handled in New York 
after this date: 

Weighing, 4 cents per tierce. 

Inspection and marking, 4 cents per tierce. 

Stripping, 50 cents per tierce. 

Nailing, 4 cents per tierce. 

Note. — The following addition was made to the Inspection Rates at a meeting of the 
Lard Trade held July 6. 1897: 

Inspection and weighing $5 per Tank of 42,500 pounds. 



EDIBLE COMPOUNDS 

93. Compounds or Shortenings. — In addition to lard 
several other classes of fats and fat mixtures have come into 
general use as shortenings. Prior to the enactment of the Food 
and Drugs Act of 1906, there were put on the market fat mix- 
tures as lard compounds or compound lards, which, however, 
contained no lard whatever. They were composed of oleo 
stearin, edible tallow, and cottonseed and other oils in varying 
proportions. Under the present regulations, however, to be 
classed as a lard compound, there must be present in the mix- 
ture a quantity of lard greater than the sum of the other ingre- 
dients. At present, the manufacture of these lard compounds, 
by the large packers at least, has been entirely supplanted by 
the preparation of the fat mixtures described here. 



58 PACKING-HOUSE INDUSTRIES, PART 1 

94. Ingredients Used in the Manufacture or Edible, 
or Cooking, Compounds. — The compounds now marketed 
consist chiefly of cottonseed oil mixed with varying proportions 
of oleo or vegetable stearins. The proportions of the different 
ingredients vary according to the season of the year, the 
locality in which it is to be sold, and the market price of the 
different components. In winter, these compounds are ""argely 
maniifactured to contain approximately 80 per cent, cotton- 
seed oil and 20 per cent, stearin. During the summer months, 
the compounds contain 75 per cent, of the oil and 25 per 
cent, stearin. These proportions may be varied at will or 
according to circumstances. For warm climates a summer 
formula must be used for raaking the compound, while for 
cold climates the winter formula may be used at all times. 

95. The cottonseed oil used in these compounds must be 
highly refined, sweet in flavor, odorless, and be not darker in 
color than 2.5 red, and 20 yellow, on the Lovibond Tintometer 
scale. 

The oleo stearin is pressed from the highest grade of beef 
fat known as No. 1 oleo stock. It should be white in color, 
sweet and nearly odorless, with a titer of 50° to 51|° C, and 
the fatty acid never exceeding .40 per cent. 

The vegetable stearin is a highly refined, hydrogenated or 
hardened vegetable oil, usually cottonseed oil. In appear- 
ance it closely resembles oleo stearin, but is much harder, as 
the titer runs from 58° to 62° C. It may be noted that the 
vegetable stearins are simply liquid fats or oils which have 
been caused to take up or absorb hydrogen whereby they are 
converted into solids. 

96. The cottonseed oil as received from the refiner is much 
too dark in color to enter into the manufacture of these com- 
pounds. For this reason it is customary to bleach the oils with 
mixtures of fullers' earth and charcoal. In bleaching the oil is 
pimiped into large, open tanks holding as much as 30,000 
pounds. Large propeller-shaped agitators keep the oil con- 
stantly in motion, and enclosed steam coils raise the temperature 
to 230° F., with the subsequent elimination of practically all 



PACKING-HOUSE INDUSTRIES, PART 1 59 

of the moisture. If any moisture remains it will be absorbed 
by the earth, forming a paste, with resulting failure to effect a 
bleach. When the moisture is expelled the proper amounts of 
earth and charcoal are added and agitation continued until a 
sample pumped through the filter press shows that the desired 
bleach has been obtained. The stearin is then added and 
when melted the whole is pumped through the press into the 
receiving tanks. After deodorizing the compound is subjected 
to certain processes which in some plants are as follows: The 
melted compound flows onto a lard roll, or cooling cylinder, as 
illustrated in Fig. 6. As the cylinder revolves the chilled 
compound is scraped off into a trough called the picker-pan 
where revolving paddles beat air into it. A spiral conveyer 
delivers it to a pump by which it is forced into the desired 
containers. 



392-5 



PACKING-HOUSE INDUSTRIES 

(PART 2) 
Serial 414B Edition 3 

VARIOUS ANIMAL PRODUCTS AND 
THEIR DISPOSITION— (Continued) 



THE FHTER PRESS IN THE PACKING HOUSE 

1. The use of the filter press in the packing house is, 
comparatively speaking, of recent date. This press is used 
for many operations and for the preparation of many packing- 
house products, among them being lard, oils, tallows, glues, 
and, at times, beef extract. The principal advantages of a 
filter press are: (1) The largest possible filtering surface in 
the smallest possible space; (2) the facility of forcing the 
material through the filtering cloth by the most suitable pres- 
sure which varies from a slight pressure to a working pressure 
of 1,000 pounds to the square inch; (3) the ease with which 
the filter press may be handled ; and (4) the rapidity of filter- 
ing large quantities of material at a very nominal cost. 

2. Construction of Filter Press. — ^Filter presses are 
made with both square and round plates and are of all 
size and capacities. The square press, while not so conven- 
ient to handle as the round one, will hold more stock and 
on this account is more desirable for packing-house use. 
The series of round or square plates of cast iron, or other 
suitable material is hung on the press rods. The plates 

COPYRIGHTED BY INTERNATIONAL TEXTBOOK COMPANY. ALU RIGHTS RESERVED 



PACKING-HOUSE INDUSTRIES, PART 2 



have concave faces on each side, the rim, or outer edge, being 
finished smooth and sufficiently wide to avoid unnecessary 

wear on the filter 
cloths and the 
forming of tight 
joints. The con- 
cave surfaces of the 
plates are provided 
with grooves by 
means of which the 
filtered material 
passes off. A hole 
in the center of 
each plate affords 
a channel through 
which the material 
to be filtered is 
forced when the 
press is charged. 

3. Fig. 1 illus- 
trates a press of 24- 
inch square plates 
that is capable of 
producing an inch 
cake (between the 
plates) and has a 
working pressure of 
150 pounds per 
square inch. One 
chamber of this 
press will hold 484 
cubic inches of ma- 
terial to be filtered. 
A press like this will 
filter from 7,000 to 
8,000 pounds of lard 
per hour. 




PACKING-HOUSE INDUSTRIES, PART 2 3 

4. Fig. 2 illustrates a single plate of a filter press, a view 
of the perforated metal front and also of the center clamp 
being shown. This plate has an outlet cock attached for 
drawing off the filtered material. The plates are covered 
with the filter cloths which are placed on each side, and are 
fastened at the center by means of adjustable screw nuts. 
These plates are also held in place by adjustable fastenings, as 
shown. When all the plates are covered with the cloths they 
are forced together by a follower which is actuated by a screw, 
and are tightened by a long lever; or, in some cases, depend- 






FiG. 2 



ing on the form of press, by a lever wheel, or by a hand- wheel 
ratchet lever. Different presses are provided with different 
means of closing. 

5. A recent improvement on filter-press plates is shown 
in Fig. 3. This improvement consists in having a delivery 
channel at the bottom of the plate, as shown. This channel, 
it is claimed, increases the capacity of the filter plate 25 per 
cent. These plates are made both round and square and with 
a corrugated or a pyramidal surface, the latter being shown 
in the figure. 

6. Filter-Press Cloth. — ^An important condition in the 
attainment of satisfactory results consists in the filter-press 
cloths being of good material. The fabric must be pliable 



4 PACKING-HOUSE INDUSTRIES, PART 2 

3^et closely woven, so that while giving a clear filtrate it will 
be sufficiently strong to withstand the heavy pressure exerted 
by the pump when forcing the oil or the lard through the 
press. Either heavy drilling or cotton duck is suitable for 
packing-house use. 

7. Operation of tlie Filter Press. — When the pump 
is running the material to be filtered is forced through the 
center channel, filling all the chambers in the plates. The 
pressure forces the liquid through the cloths to the surface 




of the plates and it passes down the grooves, or channels, on 
the face, through the outlets a, Fig. 1, in the plates, and then 
into the receptacle, or trough, b beneath. The impurities 
and bleaching material, such as fullers' earth, are retained 
by the cloths. 

The filter press is provided with a safety valve, or outlet, c 
through which when undue pressure is exerted on the press 
by the pump the material may find an outlet. This safety 
valve prevents the press or the cloths from bursting, which 
is liable to occur when wet or moist clay is mixed with lard, 
tallow, or similar material and efforts are made to force this 
mixture through the filter press. The valve may be set to 



PACKING-HOUSE INDUSTRIES, PART 2 5 

operate at any desired pressure, but for packing-house work, 
150 pounds per square inch is sufficient. Some filter presses 
are built with a top feed, the valves being so arranged that 
only a part or all of the press may be used at one time. 

It is sometimes desirable to filter quantities so small as 
not to fill all the plates of the press. In this case a blank, 
or dummy, plate, which is a solid plate without a center 
channel, is used to cut off any portion of the press. To use 
the dimimy plate, it is inserted between any two plates where 
the flow is to be cut off. For example, if only five chambers 
of the press are wanted for use, the dummy plate is inserted 
between the fifth and sixth plates and the press screwed tight. 
In this manner, a perfect working press of five chambers is 
made. The dummy plate is very convenient and should 
accompany every filter press. 



TAULOWS, GREASES, AND OILS 



KINDS OF TAIiLOW 

8. Tallow is the rendered fat of cattle, calves, and sheep, 
being for the most part inedible and largely consumed by 
the soap-making industry. The small portion of the tallow 
which is edible is consumed in the manufacture of oleomar- 
garine and cooking compounds. Goats are occasionally slaugh- 
tered in the packing houses of the United States but their 
number at the present time is of no industrial importance 
(see Packing- House Industries, Part 1), although their fat 
may also be rendered into tallow. 

The tallows rendered in the packing house include edible, 
extra-prime, No. 1, and No. 2, the three latter being inedible. 
Sometimes other tallows are produced having special designa- 
tions, but the ones mentioned are the ones usually produced. 

9. Edible Tallow. — The highest grade of tallow is that 
known as edible tallow, which, as the name implies, is used in 
food compoimds or as a cooking fat. It is made of high-grade 



6 PACKING-HOUSE INDUSTRIES, PART 2 

beef fats that have been subjected to thorough washing in ice 
water so as to remove the blood and other impurities before 
placing them in the tank for rendering. The fat undergoes 
another washing in the tank, this time, however, in heated 
water. The tank is then closed and the fat is rendered under 
pressure. Fats from which edible tallow is made are of a grade 
suitable for the making of oleo oil and stearin but are of a 
troublesome, small size. 

The material is carefully rendered in the usual manner, 
especial care being taken, however, not to subject it to too 
high a temperature or to cook it too long. A pressure of 25 
pounds of steam per square inch for 8 hoiurs will give good 
results in making a high-grade material. As an advanced 
price over the regular prime tallow is always obtained, the extra 
preparation and care is thus repaid. This tallow is now exten- 
sively made, as the demand for it is very great, being used for 
the manufacture of lard and edible cooking compounds. The 
hardness, or titer, of this product is not of such moment as 
the amotmt of free fatty acid which must not exceed J per cent. 

10. Extra-Prime Tallow. — Extra-prime tallow is made 
principally from straight-rendered fats which are not quite 
good enough for edible purposes. All fatty materials from 
which this tallow as well as the No. 1 and No. 2 tallows are 
prepared, is carefully graded and washed before being sent to 
the tank house. This is done in circular washers designed for 
the purpose, after which the material is again sorted and put 
into the tank. The grading of the fatty stock before rendering 
assists in maintaining a uniform product while the washing 
serves to remove impurities that would cause the tallow to be 
much darker in color. The material is cooked in the tank, a 
pressiu-e of 30 poimds of steam per square inch for 5 hours 
being usually sufficient. It is for the most part prepared from 
dirty fats from the oleo and other departments handling edible 
products, condemned and dead carcasses other than hog, 
bruised and dirty fats from the killing floor and other fats of 
light color and low fatty acid. The color of this material when 
drawn into barrels and chilled must be a clear yellow and not 



PACKING-HOUSE INDUSTRIES, PART 2 7 

grayish or of any decided shade ; if white and clear, it is more 
desirable. The fatty acids should not be above 2.5 per cent, 
and the titer should be 43.5 to 44.5°. It is used in the manu- 
facture of tallow oils and soaps. 

11. No. 1 Tallow. — The No. 1 grade of tallow differs 
from the preceding only in the nature of the material from 
which it is rendered. It is darker in color and has more or less 
lean tissue adhering to it from which it is separated by the 
steam pressure in the rendering tanks. It is manufactured 
largely from waste guts and intestines and trimmings from 
these when used for edible purposes. Included also are trim- 
mings from the hide cellar, meat scraps from the canning room, 
all condemned guts from beef, sheep, and calves, and certain 
catch-basin skimmings. The stock for No. 1 tallow is sub- 
jected to soaking and washing before rendering, as, in common 
with all material of this nature, the more washing it receives 
the better will be the resulting product. As this material is 
nearly always accompanied by more or less filth, slime, and 
dirt, vigorous washing is frequently necessary in order to 
produce a tallow with the characteristics demanded in this 
grade. 

The same cooking that is given to the extra-prime tallow 
is given to this. While the color and cleanliness of the product 
are of importance, the sale price is in reality based on the free 
fatty acid, titer, and the M. I. U. These three letters are the 
trade name or abbreviation for moisture, impurities, and 
unsaponifiable, the latter being the amount of the material 
that cannot be converted into soap. The free fatty acid is 
usually under 6 per cent, and the titer 43.0 to 44.0° C, while 
the M. I. U. will rarely exceed 1.5 per cent. If the fatty acid or 
M. I. U. exceed the figure given or if the titer is less than the 
above, a certain deduction in the sale price of the tallow is 
customary. As these values are of such importance both to 
producer and consumer, a detailed method for their deter- 
mination will be given later. 

12, No. 2 Tallow. — The grade known as No. 2 Tallow 
is made of all tallow-yielding material not of a grade suffi- 



8 PACKING-HOUSE INDUSTRIES, PART 2 

ciently high to have entered into the classes mentioned before. 
It is usually composed principally of catch-basin skimmings 
and rendering from offal and low-grade material such as the 
pressings of beef tankage and fertilizer material. The poor 
character of the material entering into this tallow makes no 
special standards or requirements for this grade possible. Each 
lot, therefore, is sold on its own merits, as regards the features 
just stated, and also the free fatty acids and the titer. It is 
used largely in the manufacture of low-grade soaps with its 
accompanying by-product, glycerine, and for distilling into 
oleic and stearic acids. When the percentage of free fatty 
acids is excessive, this tallow cannot be used profitably for the 
manufacture of soap and glycerine. The color is always dark 
and varies widely from yellowish-green to brown. The free 
fatty acid may vary from 15 to 30 per cent, or even higher. 
The titer is usually from 41 to 43° C. 

13. Cake Tallow. — The name cake tallow is derived 
from the shape of the finished product. This tallow is of 
good grade and has a titer of at least 44° C. The form, or 
shape, of the cakes is a matter of individual judgment, the most 
common form, however, being a cake about 3 inches thick 
and 6 inches square. The cakes usually weigh 5 pounds each, 
and they are generally packed in boxes having a capacity of 
twenty cakes. 

Cake tallow is generally white in color, but need not be, if 
the requirements as to hardness and freedom from impurities 
are acceptable. The harder the tallow the better it suits 
the consumer. This tallow is made by running the warm 
and molten tallow into sheet-iron molds of the required dimen- 
sions and chilhng quickly by any convenient means, without 
allowing the material to grain by separating into oil and 
stearin. The cakes when thoroughly chilled may be easily 
knocked from the pans and immediately packed. 

This tallow costs about J cent a pound more to make than 
tierce tallow, but the selling price greatly exceeds this extra 
cost. It is a very profitable article of manufacture. Cake tallow 
finds use in the limiber regions, both for lubricating machinery 



PACKING-HOUSE INDUSTRIES, PART 2 9 

and for lubricating the runways for logs. In the lumber 
industry, owing to its general utility, this tallow has not yet 
been replaced by oils. When tallow suitable in all respects 
for cake tallow, except in hardness, is wanted for this purpose, 
an addition of a few per cent, of tallow stearin will enable it 
to fill the requirements. 

14. Mutton Tallow. — Where large numbers of sheep 
are slaughtered the tallow from the offal is cooked by itself 
and produces a white, hard tallow known as mutton tallow. 
The usual method is to cook the heads and other material 
other than lungs, livers, and feet, in an open vat with live 
steam for 10 to 12 hours. After a period of settling the result- 
ing tallow is collected, freed from water, and tierced. The 
offal from the intestines, feet, etc., produces a dark-colored 
material, which is tanked with the usual material for No. 2 
tallow. 

The tankage remaining from the open cooking in the vats 
is again cooked under pressure with the ordinary No. 1 tallow 
stock, materially contributing if in any quantity, to raising 
the titer of that grade. Mutton tallow has a titer of 44° to 48° 
C, the latter when made of the caul and kidney fat. This 
tallow is very useful for making cake tallow. 

15. Yield of Tallow. — The yield of tallow from fat is 
extremely variable, depending very much on the material 
from which it is made. When the total fat of a bullock other 
than that left with the dressed beef is tanked, the yield 
approaches from 74 to 78 per cent, of tallow. This includes 
the caul fat and other parts generally selected for oleo oil 
and stearin. This yield can be increased to 80 per cent, by 
careful and thorough pressing of the cooked tankage after 
rendering. 

When the general run of fat for ordinary tallow is tanked 
and the highest grades removed, the yield approximates from 
68 to 78 per cent, of the material cooked. The amount of 
tallow obtained in all cases depends on the quality and fat- 
ness of the animals slaughtered, and on the care taken in 
rendering. 



10 PACKING-HOUSE INDUSTRIES, PART 2 

The yield of tallow from bones, as with other things, is 
exceedingly variable. This tallow is in reality a bone oil. 
It is a soft, yellowish-white material that may be and at times 
is utilized in making the lower grades of oleo oil. The tallow 
obtained from the heads of cattle is the same material as that 
derived from the other bones. It has a titer of about 42° to 
42.5° C. 

Kidney fat when tanked by itself may be made to yield 
from 90 to 95 per cent., the latter in exceptional cases. 
Caul fat and ruffle fat when cooked under pressure will 
yield from 78 to 84 per cent., depending on the quality of 
the cattle from which these fats are taken. 



GRBASGS 

16, Classification. — Greases are considered as inedible 
fats intermediate in hardness between tallows, which are hard 
fats, and oils, which are liquid fats. They are derived exclu- 
sively from the hog, as there is no advantage in putting the 
fat from other animals into this class. Being too soft for use 
in the manufacture of soaps, the greases serve the sole purpose 
of pressing into lard oils and stearin. It is common practice 
to produce four grades of greases depending on the color and 
free-fatty -acid content, although this ntunber is often modified 
in the different establishments. In the order of their value, 
these grades are known to the trade as, A white, B white, 
yellow, and brown grease. 

17. Grade A White Grease. — The first grade of inedible 
fat from the hog is known as Grade A White Grease, being 
practically white in color and having a fatty-acid content 
under 2 per cent. It is made from material that would ordi- 
narily produce lard had it not been contaminated diu-ing the 
process of manufacture. It is very similar to lard in appearance, 
odor, and color, and is a lard except in name and purity. All 
hogs condemned before or at slaughter and condemned-pork 
material furnish the source of this grease, together with other 
material of high gi'ade. The stearin from it is not sold as lard 
stearin, but must be branded grease stearin. 



PACKING-HOUSE INDUSTRIES, PART 2 11 

18. Grade B White Grease. — Grade B White Grease 
is very similar to the preceding, being somewhat darker in 
color and higher in free fatty acid. This figure may at times 
reach 10 per cent. This grease is obtained from material that 
is not dark in color or discolored, the resulting grease being 
of a light-fawn or buff color, and having a strong, more or less 
rank, odor. Boiled-out ham grease, sausage-room grease, gut 
and trimming-room fats furnish a plentiful source of fats for 
this grade of grease. 

19. Yellow Grease. — The grade known as yellow grease 
is made of rather dark-colored material or good-grade material 
intermixed with a small quantity of poor material. For ex- 
ample, grease from ham boiling, which by itself is B white, 
when mixed with grease from the livers, lungs, etc., becomes 
yellow grease. In small establishments where all grease mate- 
rial is cooked together, the resultant product is yellow grease. 
This grease has a strong, rather nauseating odor, and the 
color, as the name indicates, is yellowish. On pressing, yellow 
grease yields No. 1 lard oil and yellow-grease stearin. If light 
in color, the yellow grease may yield an extra No. 1 lard oil. 

20. Brown Grease. — The grade known as brown grease 
is made of all refuse grease-yielding material in the packing 
house. The pressed-out grease from tankage is used for this 
purpose. The dark-colored, greenish-black grease yielded from 
livers, lungs, and floor scrapings is brown grease. It is also 
consumed in a small way in the manufacture of cheap soaps, 
axle grease, etc. When this material is pressed, No. 2 lard oil 
and brown-grease stearin are obtained. Brown grease from 
hog material corresponds with No. 2 tallow from beef material. 

21. Methods of Obtaining Grease. — Greases are ob- 
tained from the fatty material in the same way as lard. 
Greases of good grade are washed in the tank in the same 
way as lard material, but with the lower grades such as yel- 
low and brown, no washing is performed. In fact, it would 
be a waste of time and labor to wash the cheaper grades. 
Even if the grease were raade a shade or two lighter than 



12 PACKING-HOUSE INDUSTRIES, PART 2 

usual, it would command no higher price on account of 
this single characteristic. The tankage from grease mate- 
rial is treated as the regular lard tankage. 



OIL.S 

22. Kinds. — Oils is the collective name given to the 
various grades of oleo oil, lard oil, tallow oil, and neatsfoot 
oil. By oil is meant that portion of a grease which when 
separated from the stearin of the grease remains a liquid at 
ordinary temperatures. In other words, a stock, or tallow, or 
grease, is only a mixture composed of a soft and a hard portion. 
The hard portion is known as stearin and the soft portion as 
oil. The two portions are separated from each other by means 
of a press. The particular manner in which the various oils 
and stearins are handled will be described later. 

The grade of oil depends upon the grade of beef stock, 
grease, tallow or neatsfoot stock from which it is derived. The 
grade of stock in turn depends largely on two factors — the 
free-fatty-acid content and the color — the better grade being 
that with the lowest free-fatty-acid content and the lightest 
color. 

Oils, tallows, and greases are all chemical combinations of 
glycerine with fatty acids. Whether the material is a grease 
or a tallow depends on the nature and varying proportions of 
the fatty acids which are combined with the glycerine in that 
particular fat. Under cert am conditions, such as the presence 
of moistiire and impurities, subjection to high temperatures, 
poor and improper handling, greases and tallows split up into 
glycerine and free fatty acids. These same conditions also 
usually cause a darkening of the color. In general, this increase 
in fatty acid and darkening in color is objectionable, although 
not in all cases. The particular oils will be considered later. 

23. Oleo Oil. — The third item of value obtained from the 
bullock after the dressed beef and the hide, is the fat, from 
which is manufactured the edible oleo oil and the oleo stearin. 
Prior to 1871, practically none of the fat from the bullock was 



PACKING-HOUSE INDUSTRIES, PART 2 13 

used for food but almost exclusively for soap and other manu- 
facturing purposes. About that time it came into use in the 
preparation of butter substitutes, which increased in popu- 
larity until the trade has reached its present tremendous pro- 
portions. The manufacture of oleo oil forms a most profitable 
outlet for the large part of the fat of the bullock that other- 
wise would be rendered into ordinary tallow. In the manu- 
facture of oleo oil scrupulous cleanliness is a most important 
consideration, as without it no first-class product can be ob- 
tained, even if the best material is used. While cleanliness 
is important, necessary, and even obhgatory everywhere in 
the packing house and with all products, oleo oil is probably 
the most sensitive to deterioration on account of unclean 
surroundings. 

Depending on conditions at the time, it is customary to 
manufacture as many as four grades of oleo oils. The No. 1, 
or highest, grade is of neutral flavor, light in color, nearly 
odorless, and has a melting point of from 85 to 90° F. The fatty 
acid is under 0.40 per cent. It is usually made from the ruffle 
fat, caul fat, gut-end fat and all other carefully selected fats 
of neutral flavor. The No. 2 grade differs from the preceding 
wholly in the more pronounced flavor of the fats entering into 
its manufacture. The color is slightly deeper and the flavor 
noticeable. It is made principally from kidney and cod fat, 
and machine and chip fat. The No. 3 oil is much deeper in 
color and the melting point may be as high as 95^ F. It is 
not as sweet as the other grades and it may have a decidedly 
cooked flavor. It is made largely from bone oil and kettle 
washings. A fourth, or yellow, grade of oleo oil is also manu- 
factured. It is similar in quality to the No. 1 oil, but being 
manufactured from grass-fed cattle, is much deeper yellow 
in color. It enters into the preparation of the oleomargarine. 

24. Manufacture of Oleo Oil. — The fat after removal 
from the animal is conducted through galvanized-iron chutes 
into a washing vat located in the oleo-oil department. This 
department is usually on the floor immediately below the one 
on which the animals are slaughtered. All dirt and blood is 



14 PACKING-HOUSE INDUSTRIES, PART 2 

removed in this water which is usually at a temperature of 
60 to 70° F. The cutting machine reduces the fat to small 
pieces when it is again plunged in a vat of water kept at 40° F. 
The object of putting the fat into colder water gradually is 
to avoid hard chilling on the surface of the heavier pieces. If 
this took place the animal heat would be prevented from 
escaping through this soHd part of the fat. The heat retained 
in the interior of the fat would very quickly cause it to become 
sour and unfit for the best and edible grades of oil. The fat 
remains in this second vat until the animal heat has been 
removed, and then it goes into a third vat usually chilled with 
ice. It is customary to grade or sort the fat following the first 
washing and preceding the slicing or cutting. These successive 
transfers of the fat require about 10 to 12 hours, it being kept 
in the iced water until about an hour before it is wanted for 
hashing, which precedes the melting of the fat into oil. This 
chilling further hardens the fibre surrounding the fat cells so 
that the fat is more thoroughly separated from the fibre in the 
melting tank when aided by the hashing. After passing through 
this hasher, which is merely a large, steam-jacketed sausage 
machine, the fat is ready for the melting tanks. 

The chilled beef fat is placed in the hasher and disintegrated 
the same as leaf lard. The same apparatus may be, and often 
is, employed for the manufacture of both oleo oil and neutral 
lard. The finely minced fat is allowed to flow through the 
spout 5 of the apparatus shown in Fig. 7, Packing-House 
Industries, Part 1, into the melting kettle D until the kettle 
which has been previously warmed before starting, is filled to 
within a foot of the top. The paddles attached to the shaft c 
stir the mixture continuously during the operation. Heat is 
applied gradually and continuously to the water in the jacket 
until, when the kettle has been filled with the minced fat, the 
temperature is around 155° to 160° F. 

The melting fat is cooked at this temperature for IJ hoiirs 
when the operation is completed. The paddles are raised 
free from the fat and a quantity of salt is scattered freely 
over the surface of the melted oil to cause the scrap and water 
in it to settle below the oil. The material is allowed to rest 



PACKING-HOUSE INDUSTRIES, PART 2 15 

for 20 or 30 minutes when the clear, supernatant oil is care- 
fully siphoned off by means of the attached siphon the outside 
leg of which is shown at e. 

The oil flows through a cloth strainer, to remove floating 
scrap, into the kettle F, where a further separation of fine scrap 
and moisture takes place. After remaining here at a tem- 
perature of not less than 130° F. for an hour, the oil is again 
siphoned by the pipe g into the settling kettle H. All these 
kettles are provided with water-jackets as experience has shown 
that a dry heat on oleo oil is very detrimental to its quality. 

The oleo oil remains in the final kettle for not less than 
3 hours at a temperature not over 130° F. From this kettle 
it is run into seeding trucks at a temperature of 130° F. A 
few degrees from this either way materially alters the char- 
acter of the stock, which is the term for the seeded, or grainy, 
mixture of oil and stearin. The warm material in the seeding 
trucks is placed in a room that is free from drafts and protected 
from direct sunlight and allowed to remain there for 48 hours. 
This is done so that the stock will resolve itself into the oily 
and the hard parts of the original tallow or into olein and 
stearin. The temperature of the seeding room must be steadily 
maintained at 90° F. 

The scrap and water remaining in the melting kettle D is 
withdrawn through the valve k and sent to the tallow-render- 
ing tank so as to get the tallow not obtained at the mild melt- 
ing temperature. The kettle is thoroughly cleansed, when it 
is again ready for another charge. 

25. Pressing- tlie Oleo Stock. — After the stock in the 
seeding trucks has assimied the required condition for press- 
ing, it is taken to the pressing room. The oil and stearin 
by this time are distinctly separated, yet intimately mixed. 
The material is thoroughly and uniformly mixed with the 
hands, placed in cloths laid over a mold, and wrapped in 
the form of a cake. To facilitate working these molds are 
made on a circular revolving table so that with one man 
filling cloths, one folding into cakes, and another placing 
them in the press, the work proceeds very rapidly. 

392—6 



16 



PACKING-HOUSE INDUSTRIES, PART 2 



26. The form of press used for this work is illustrated 
in Fig. 4, the iron press plates not being shown. This press 
is known as the knuckle-joint press, and is run by power. 
The speed of the press is regulated by pulleys for a rapid 
or slow descent as desired. 

27. The cloths for pressing the stock are of heavy, closely 
woven duck, strong enough to withstand the high pressure 




Fig. 4 



applied on them. This point is one of many w4iere close 
attention to small details is necessary in order to produce 
a high-grade article. Neglect of this point alone would be 
the cause of an inferior product even if all other parts of 
the manufacture were properly carried out. After each day's 



PACKING-HOUSE INDUSTRIES, PART 2 17 

run the press cloths must be thoroughly washed and dried. 
While cloths for pressing other oils may be used several times 
without washing and drying, those for pressing oleo oil are 
used only one day. 

The material folded in the cloths in the form of cakes is 
placed in the press on the bottom fixed plate until the latter 
is covered with a sufficient number of wrapped-up cakes. 
A sheet-iron plate is then inserted in the press and dropped 
on the cakes. This plate in turn is filled with material and 
another plate inserted above, this performance being repeated 
until the press is filled to its capacity, which varies with the 
size of the press used. The oily part of the stock begins to 
run out long before the press is filled, owing to the weight of 
the upper plates and material pressing on the lower layers. 
This is the oleo oil, or, as it is termed in Europe, oleomargarine. 
This term must not be confounded with the American name 
oleomargarine, which name applies exclusively to factitious 
butter, or butterine. 

The oil flows to the settling receptacle which should be 
water-jacketed, the flow of the oil being augmented by the 
ram of the press slowly descending and pressing the material. 
The speed of the press while pressing is very slow, occasional 
periods of rest from descending being allowed in order to 
give the oil time to ooze from the stearin. The operation of 
pressing is completed in about 30 minutes, but the stearin in 
the bags has the pressure left on it an hour or so longer, to 
give the material ample time to drain. When the stearin is 
free from oil, the ram of the press is rapidly raised by the fast 
motion of the press and the latter unloaded, the operation 
being exactly the reverse of filling. The oleo stearin is removed 
from the cloths by unfolding and shaking them and the press 
is then ready for another charge. The temperature of the 
press room should always be maintained around 90° F. 

There is always more or less waste incidental to the press- 
ing of oleo or any other material. This waste is practically 
recovered when washing the press cloths, utensils, etc., and 
in the case of oleo stock is placed with the tallow stearin. 
The loss on pressing is usually regarded as 1 per cent., and 



18 PACKING-HOUSE INDUSTRIES, PART 2 

tests are figured on that basis unless the loss is actually shown 
to be greater. 

28. The oleo oil from the pressing is held for a short 
settling period in the reservoir from which at a temperature 
of 92*^ F. it is drawn into tierces. These tierces are immedi- 
ately placed in a temperature of 55° to 60° F., so that the oil 
will acquire the requisite grainy condition. The temperature 
must be kept within these limits to insure successful grain- 
ing in from 5 to 6 days, and sometimes in even less time. When 
placed in the graining temperatiire, the 3-inch side bungs of 
the tierces are removed, to allow heat and any possible odor 
to escape. 

Oleo oil finds exclusive use in the manufacture of oleo- 
margarine, or butterine. The greater part of this oil is exported 
to Holland from where it is distributed throughout the various 
European markets. 

Oleo oil should have a titer not exceeding 40° C; but at 
times this may be exceeded without detriment, as the oil is 
not purchased on its titer test but on its physical character- 
istics, as noted. As the raw fat from which this material is 
made is kept in a cold, fresh condition, free fatty acids cannot 
be generated, and, consequently, the free-fatty-acid tests of 
oleo oil will show ordinarily less than | per cent. Good oleo 
oil contains only .2 or .3 per cent, of free fatty acids. The 
yield of oleo stock from fat is from 65 to 70 per cent, or more, 
and the yield from pressing the grained stock is about 50 per 
cent, each of oleo oil and oleo stearin. This percentage yield is 
governed largely by market conditions and prices, the manu- 
facturer inclining to the greatest yield in the highest -priced 
product whether oil or stearin. Oleo oil is colored at times for 
certain trades by means of pure annatto. 

29, Oleo Stearin. — After the oleo oil is pressed out as 
just described, the oleo stearin is shaken free from the cloths 
into a bin and from this it is filled into large, thin-staved 
tierces, which weigh when filled approximately 600 pounds. 
The oleo stearin is pounded as compactly as possible into 
these tierces, the object being to have as little air as possible 



PACKING-HOUSE INDUSTRIES, PART 2 19 

intermixed with the material, and also to have the tierces hold 
as much material as can be pounded in with a large wooden 
maul. For export purposes the stearin is sometimes melted 
and run into tierces, the material in this condition retaining 
its sound condition for a very long period. Oleo stearin finds 
a very large outlet in the tanning and leather trades and is 
used extensively for soap and candle purposes. It is also used 
in the manufacture of cooking, or edible, compounds. 

Oleo stearin is pressed so that it will have a titer of from 
48° to 52° C— generally averaging about 50° C. The harder 
the oleo stock is pressed, the harder the stearin will be until 
the limit is reached. This is about 52° to 53° C; but oleo 
stearin of this titer is never made commercially. To pass 
sale requirements, however, the titer must be at least 48° C. 

30. Neatsfoot Oil. — The method of obtaining neatsfoot 
oil has already been described. The grades usually manu- 
factured are as follows : extra-prime neatsfoot oil, prime neats- 
foot oil, extra No. 1 neatsfoot oil, No. 1 neatsfoot oil, and 
winter-pressed neatsfoot oil. 

While packing houses make this oil as described, neatsfoot 
oil may refer to an entirely different sort of product in the 
oil trade. An oil made from the fleshings of the tannery, and 
other tannery greases, is also called neatsfoot oil. As this oil 
differs in quality, it is sold on maker's brand, on sample, etc. 

Extra-prime neatsfoot oil is unpressed neatsfoot stock, 
natural color, imbleached, and filtered only, not cold- or winter- 
pressed. It is used by tanners, compounders of cutting oils, 
manufacturers of leather dressings, textile manufacturers, silk 
throwsters, and lace manufacturers. It is also used by 
pressers in the manufacture of cold-test neatsfoot oil. The free 
fatty acid is under 1 per cent, and the cold test is about 
45° F. 

Prime neatsfoot oil has a free-fatty-acid content of 5 per cent, 
or less and is cold pressed to 40 to 45°, bleached and filtered. 
Its uses are similar to those of extra-prime neatsfoot oil in such 
places as v/ill not be affected by the higher acid, especially as a 
tanning oil for coarser and cheaper grades of leather. It is a 



20 PACKING-HOUSE INDUSTRIES, PART 2 

shade lighter in color than the extra-prime grade, since it is 
bleached. 

Extra No. 1 neatsfoot oil has a cold test of 40 to 50° and 
free-fatty-acid content of 12 to 15 per cent. Its uses are 
similar to other grades of neatsfoot, but for coarser grades of 
work. 

No. 1 neatsfoot oil is used for much the same purposes as 
extra No. 1 with the additional use in shoe polish. The free- 
fatty acid is 18 to 20 per cent, and the cold test 40 to 50°. 

Cold-test or winter-pressed neatsfoot oil is extra-prime neats- 
foot stock which has been winter-pressed to the desired cold 
test. The free-fatty-acid content varies from 1 to 2 per cent. 
There are three grades, namely, 20 to 25° cold test, commonly 
known as 20 cold test; 30 to 35° cold test, commonly known 
as 30 cold test, and 40 to 45° cold test, commonly known as 
40 cold test neatsfoot oil. Their uses are chiefly in the leather 
and textile industries, the grade used depending on the grade 
of work for which it is desired. Its chief use is in the tanning 
of the best grades of leather. 

To press neatsfoot oil into winter-pressed oil and neatsfoot 
stearin, it is necessary to have the oil in a grainy condition. 
By this is meant a separation of the olein from the stearin — 
the solid portion of the oil. The pure neatsfoot oil in barrels 
is placed in a room having a temperature of about 32° F. and 
kept there for 4 weeks. Various unsuccessful methods to 
shorten this time have been tried. It is customary to set the 
barrels on end with one head removed. 

After the oil has obtained the condition for pressing it is 
placed in cloths of closely woven duck. The cloths when 
folded contain about 5 pounds of material. In pressing this 
oil, a double cloth for infolding the material must be used, or 
an oil of low cold test will not be obtained. The temperature 
of the press room should be kept steady, at 28° to 30° F., 
when the pressed oil, using double cloths, will have a cold 
test as low as 14° to 16° F. The manufacturers, however, 
will seldom guarantee winter-pressed neatsfoot oil to with- 
stand a cold test under 20° F., owing to the variable and 
uncertain methods of making the cold test by purchasers. 



PACKING-HOUSE INDUSTRIES, PART 2 



21 



31. Pressing of Neatsfoot Oil.— The details of press- 
ing neatsfoot oil are as follows: The cloths are placed on 
an upright wooden mold made so that the cloths when folded 
form a bag about 9 in. X 6 in. X li in. These bags are placed 
on the bottom of the press, Fig. 5, with room between them to 
allow for the spread in pressing. A plate of sheet iron is then 

placed on these, thus forming 
another bottom for making the 
second tier of bags. This opera- 
tion is repeated until the press is 
filled with layers of bags alter- 
nating with the separating 
plates of iron. The top plate b is 
usually of wood strong enough to 
withstand the pressure without 
bending, thus keeping a flat 
surface and an equal pressure on 
the top layer. The chains attached 
to the ratchet h are then con- 
nected to the bar c on both 
sides by means of iron links. 

The slack in the chains is 
taken up by raising and lower- 
ing the lever k until the lever 
remains raised in the air. The 
framework a, a of the press is 
made of strong angle iron in 
which the plates fit 
easily at the cor- 
ners, so that they 
can follow down the 
pressed bags of oil. 
The lever k, at first without weights, is raised as soon as it falls 
to the floor. When the resistance offered by the material in the 
bags keeps it from falling, a cast-iron weight m is placed on one 
of the notches in the lever, and the lever thus weighted is again 
raised as fast as it falls to the floor. When the lever remains sus- 
pended with one weight another weight m' is added, and the 




22 PACKING-HOUSE INDUSTRIES, PART 2 

same performance is repeated until, with both weights on, the 
lever remains in the air. The material in bags during this time 
is being constantly deprived of the liquid portion, which flows 
to the reservoir through g from the pan /. This oil is neats- 
foot oil of low cold test, not congealing much above 14° F. 
The cold test of the oil above this point may be regulated by 
the temperature of the press room, but it is neither practicable 
nor profitable to produce oil that will withstand a lower cold 
test than that just mentioned. 

The time required to complete the pressing is about 3 days, 
the pressing proceeding very slowly after the bulk of the oil 
has oozed out. The lever must be frequently raised during 
the first day, and thereafter about twice every 24 hours. 

The form of press shown in Fig. 4 is also extensively em- 
ployed in pressing neatsfoot oil and greases and may be used 
to advantage where circumstances permit. 

32. The material remaining after pressing is actually 
neatsfoot stearin, but it is seldom sold as such. The close 
approach in its nature, composition, and cold test to tallow 
oil makes its sale as that commodity legitimate. In warm 
weather neatsfoot stearin may be sold for neatsfoot oil, since 
the cold test at this season is not important. This stearin may 
also be returned to the ordinary neatsfoot oil where the cold 
test is not essential. 

The bags, or cloths, are shaken free from the pressed 
material, when they are ready for use again without wash- 
ing. Cloths for pressing neatsfoot oil may be used four or five 
times without washing, but the texture is gradually closed 
up by wax-like stearin, which must be removed. The neats- 
foot stearin is simply melted and either barreled for neatsfoot 
oil or used and sold for tallow oil. 

Winter-pressed neatsfoot oil is extensively employed as a 
lubricant for very fine instnmients. The pressed oil is usually 
heated to eliminate accumulated moisture and is filtered to 
remove extraneous contaminations and dirt. The pressed oil 
may be but seldom is bleached white by means of fullers' earth. 
The sale for this class of oil is very limited. The process of 



PACKING-HOUSE INDUSTRIES, PART 2 23 

bleaching is in every way similar to the bleaching of lard, which 
has already been described. 

33. Lard Oils. — Lard and grease are used for making 
lard oils, the operations being carried out in the same kind 
of presses that are used for pressing neatsfoot oil. The press 
shown in Fig. 4 is the more modern style and gives quicker 
results. While the form of press shown in Fig. 5 is largely 
used, it is being replaced wherever possible by the knuckle- 
joint press. In large establishments several of these presses, 
Fig. 5, are arranged side by side, the pan / being made suffi- 
ciently long to accommodate all the presses. One outlet g 
serves to drain the oil from all the presses. The axles of the 
presses are placed at such an angle that the levers clear them- 
selves in falling. The advantage of arranging several presses 
in this way is that while one press is having the material pressed, 
another may be filled. As it requires from 2 to 3 days to press 
oil out of lard and grease, the advantage of such an arrange- 
ment is obvious. 

34, Pressing of Lard Oils. — The same method as that 
just described is used for pressing lard and greases. Much 
greater care, however, is required in handling the lard both 
before and after pressing, than is necessary with greases or 
ordinary lard oils. 

The lard is made into a grainy condition suitable for press- 
ing. The more marked and complete the separation of the 
olein and stearin of the lard, the better and easier it can be 
pressed. Lard or grease that has not been made into a grainy 
condition is not susceptible of pressing, as the oil and stearin, 
being intimately mixed and in a smooth, plastic condition, 
resist separation by pressure. To obtain the material in the 
requisite form, the lard or grease, after being filled into the 
receptacles in a molten condition, is allowed to remain quiet 
for 3 or 4 days in a temperature of about 60° F., when the sepa- 
ration of the material takes place. A longer period of graining 
will do no harm and at times is a positive advantage as under 
favorable conditions a most complete separation of the oil and 
stearin ensues, enabling the lard oil to be dipped from the stearin 



24 PACKING-HOUSE INDUSTRIES, PART 2 

almost completely. Many small concerns are thus in a posi- 
tion to obtain oil and stearin without the use of a press. This, 
however, is not a general way of obtaining the lard oils. 

The grainy lard or grease is filled into cloths in the same 
manner in which neatsfoot and oleo oils have been and is 
placed in the press, layer on layer, until the press is filled as high 
with material and plates as practicable. The process is similar 
to that of pressing neatsfoot oil. With lard and grease, a single 
cloth is sufficient to permit the lard oils to flow through and 
at the same time retain all the stearin in the cloths. 

35, Grades of Lard Oils. — Eight grades of lard oils are 
ordinarily manufactured, although certain presses may market 
a larger or smaller number. These grades with a brief descrip- 
tion of each, follow: 

Prime winter strained lard oil is used largely by railroads 
and oil compounders in making signal oil and in the manu- 
facture of fine lubricating oils and by silk and textile manu- 
facturers in the preparation of spindle lubricants. The free- 
fatty-acid content of this oil is under 2 per cent, with a cold 
test of 45°. 

Special prime lard oil is specially prepared for use as burn- 
ing or signal oils, meeting all requirements for this class of oils. 
The free acid and cold test are the same as for the preceding 
grade. 

Extra winter strained lard oil is used largely by compounders 
of fine lubricating oils of various kinds, especially for high- 
speed and splash oils and also by silk and textile manufacturers 
for spindle lubricants. It is sometimes used by brass manu- 
facturers in moulding operations. The free fatty acid may 
run as high as 4 per cent, and the cold test the same as the 
above two grades. 

Extra lard oil is used for practically the same purposes as 
the preceding, the main difference in the oil being that the 
fatty acid may be as high as 5 per cent. 

Special extra No. 1 lard oil is used largely by machine shops 
for screw and thread cutting and all kinds of machine cutting 
of better grades. It is also used in making compounds of lard- 



PACKING-HOUSE INDUSTRIES, PART 2 25 

oil substitutes used for the same work. It is sometimes used 
in the manufacture of lubricants and by gun manufacturers 
for rifling guns. The cold test runs from 45 to 50° and the 
fatty acid from 7 to 9 per cent. 

Extra No. 1 lard oil usually runs from 12 to 15 per cent, free 
fatty acid and the cold test from 45 to 50^'. Its uses are similar 
to those of the grade immediately preceding. 

No. 1 lard oil is used for all kinds of coarse thread, screw, 
and die cutting, and by compounders of thread and die-cutting 
compounds and cheaper lubricants. It is also used to some 
extent in the textile trade for the manufacture of lower grades 
of cotton and woolen fabrics and carpets, to soften the product 
in the manufacture. The cold test runs from 45 to 50° and 
the fatty acid from 18 to 20 per cent. 

No. 2 lard oil finds uses similar to the preceding oil and for 
coarser cutting such as bolt cutting. The free fatty acid is 
from 25 to 30 per cent, and the cold test from 45 to 50°. 

36. Bleadiing- Requirements of tlie Several Grades 
of Lard Oils. — All the oils after pressing are allowed to 
settle in the receiving tanks until a sufficiently large quantity 
has accumulated to filter and, if necessary, to bleach. The 
oil is placed in the bleaching tank, the air blower started, and 
the oil heated and agitated until the temperature reaches 
160° F., when the necessary quantity of fullers' earth is added 
and the hot oil and suspended clay are pumped through the 
filter press. The bleached and filtered oil is sent to the storage 
tanks from which, after the oil has been allowed to cool 
to normal temperature, it is drawn into the regulation oil 
barrels. It is necessary to allow hot oil to cool before filling 
the barrels. This is done so that the oil will not acquire 
cloudiness in the barrels while cooling. Such oil is technically 
termed of. 

It is evident that the color of lard oil will depend on the 
color of the grease from which it is pressed. When the color 
of the oil is not up to the standard set by the free-fatty-acid 
and cold test, it is customary to bleach the oil by the above 
process. 



26 PACKING-HOUSE INDUSTRIES, PART 2 

37. Lard and Grease Stearins. — After the oil has 
been pressed from the material the stearin remaining is shaken 
free from the press cloths, and when a sufficient quantity of 
it has accumulated, it is melted, mixed to insure uniformity, 
and run into tierces. 

Lard stearin is used to stiffen refined and mixed lards, 
thereby causing such lards to withstand warm weather without 
melting. This stearin is only rarely used in lard compound. 

Grease stearins are divided into several grades correspond- 
ing to the greases from which they are made. That from 
grade A white grease is branded white-grease stearin and is 
used by soap manufacturers. The stearins from grade B 
white and yellow grease are both classed as yellow-grease 
stearin, no distinction being made between them. This stearin 
is used almost exclusively in soap manufacture, having a 
titer somewhat higher than the usual trade tallow; large 
quantities are also exported. Brown-grease stearin is seldom 
met with in trade, it usually, and then very rarely, being made 
on order in the packing houses. This material is used for dis- 
tilling into olein and stearin and at times for soap making. 

The requirements of stearins are limited to the titer, or 
hardness, and the amount of moisture and impurities they 
contain. The titer required of lard stearin must be at least 
44° C., and it must not contain over 1 per cent, of moisture 
nor any impurities. White-grease stearin, as well as yellow- 
grease stearin, is sold at a price corresponding to its hardness 
and the amount of moisture and impurities it contains. These 
stearins are usually pressed to a hardness of 43° or 44° C., and 
contain, as a rule, less than 2 per cent, of moisture and impu- 
rities combined. The rapid methods of determining these, 
as practiced in packing-house laboratories and at the pres- 
ent day by many tallow and grease brokers, will be given 
later. 

38. Tallow Oil. — With the exception of modifications 
as to temperature in pressing, tallow oil is made similarly 
to lard oils. Like lard and grease, the tallow must be in a 
grainy condition before it can be successfully pressed; and, 



PACKING-HOUSE INDUSTRIES, PART 2 27 

similarly, the better the separation of the olein from the stearin 
in the seeding receptacles, the quicker and better the separa- 
tion of the oil in the press. 

The molten tallow for pressing is drawn into suitable recep- 
tacles such as open-headed barrels or trucks and allowed to 
stand for 5 days at a temperature of from 75° to 85° F. The 
tallow by this time will have resolved itself into the components 
of oil and stearin and is ready for pressing. It is unwise to allow 
the grained tallow to remain without pressing longer than this 
period, as the stearin grains will constantly increase in size 
and unite with the olein, in consequence of which it will be 
very difficult to press out the required yield of oil. 

39. Pressing and Bleaching Tallow Oil. — The grained 
tallow is manipulated in the same manner as grease, and 
when made ready in the cloths for pressing, it is filled into 
the mold in the way already described. The cakes are placed 
in the press, Fig. 4 or Fig. 5, and the operation is completed 
in the usual way. The tallow is pressed for 2 or 3 days at a 
temperature of about 85° to 90° F. The higher the tempera- 
ture of the press room, the greater will be the yield of tallow 
oil ; but, on the other hand, the cold test of the oil will be quite 
high owing to the greater quantity of stearin melted into the 
oil. This procedure of pressing at a high temperature is prac- 
ticed at times when the price of the oil is higher than that of 
the tallow stearin. The usual yield, however, is from 45 to 50 
per cent, of oil from the tallow. 

The oil is conducted to a reservoir until a sufficient amount 
has collected for filtering and, if necessary, for bleaching. 
Tallow oil is ordinarily of a very light yellow or white color. 
If the pressed oil is satisfactory in color, it is bleached in the 
usual manner by from 3 to 6 per cent, of fullers' earth, depend- 
ing on the stock. The temperature at which the material is 
bleached is of no particular consequence, as this oil is not 
used for food purposes. A good temperature is around 140° 
F. The oil need not be bleached to a water-white color, as this 
is not an essential. This oil is used in compounding with 
mineral lubricating oils. 



28 PACKING-HOUSE INDUSTRIES, PART 2 

40, Acidless Tallow Oil. — The first step in procuring 
acidless tallow oil is to obtain the ordinary tallow oil as just 
described. In selecting tallow for this purpose, it should not 
exceed 4 or 5 per cent, of free fatty acids, as, when pressed, 
these free fatty acids are practically doubled in their relative 
percentages in the pressed oil, the material left in the cloths — 
tallow stearin — retaining a very small part of them. The less 
free acid a tallow contains the less shrinkage will there be in 
the operation of making it acidless. The operation is carried 
out in the following manner : 

The oil is brought into the treating tank which is similar 
to the bleaching tank shown at A, Fig. 5, Packing-House 
Industries, Part 1, and may be used as such, the suitable con- 
nections being provided. This tank must have the cock m 
about 4 or 5 inches wide in order that the soap formed may 
be withdrawn through it. The other attachments of this 
tank are the same as for the regular bleaching tank. The 
oil is brought to a temperature of from 125° to 135° F., and 
the percentage of free fatty acids having been previously 
ascertained, sufficient solution of caustic soda is added to 
combine with the free fatty acids present. The caustic solu- 
tion is made with a strength of 20° Baimie, as this strength 
has been found best for this purpose. During the addition of 
the alkali the oil is constantly agitated with the air blower. 

In a few minutes the reaction is complete, when the oil is 
allowed to stand at rest for 5 minutes to allow the soap formed 
by the combination of the alkali and the fatty acids to col- 
lect on top of the oil. A portion of the soap will sink to the bot- 
tom with the excess of water. The floating soap is removed 
by skimming and the soap in the bottom of the tank is removed, 
together with the water, through the cock m. The oil is then 
agitated to cause the remaining soap to gather together. This 
soap is also removed in the same manner and the oil is now 
washed with clean water and agitated strongly with the air 
blower. This washing serves to remove the last traces of 
soap and any excess of alkali present. The wash water is then 
drawn off and the oil is heated to 165° or 170° F. and blown 
until the last traces of moisture have been removed. The oil 



PACKING-HOUSE INDUSTRIES, PART 2 29 

is now ready for bleaching and filtering which are carried out 
in the usual manner. Acidless tallow oil is always bleached 
after being made acidless and, as mentioned before, the same 
tank may be made to serve for the complete operation. 

41. The chief trade requirement of acidless tallow oil is that 
it shall contain not more than J per cent, of free fatty acids. 
The cold test of this oil is of no material importance, although 
it is generally made to stand a test of about 65° F. Other con- 
ditions being equal, the whiter the color, the more acceptable 
is the oil. 

Acidless tallow oil finds its greatest use in compounding with 
mineral lubricating oils, where the absence of all acidity is 
of the highest importance. It is also used alone as a lubri- 
cant for machinery. This oil, as made in the large packing 
houses, seldom contains over .2 per cent, of free fatty acids. 
The soap formed in the manufacture of acidless tallow oil, 
when a sufficiently large quantity has accumulated, is decom- 
posed with sulphuric acid of 66° Baume in a lead-lined tank. 
The resulting fatty acids, black in color, may be mixed if 
desired, in small quantities at a time, with No. 2 tallow. 

42. Tallow Stearin. — The material remaining in the 
cloths in the press after the oil has been pressed out of the 
tallow is tallow stearin, corresponding to the grease stearin 
resulting from the operation of pressing grease. The tallow 
stearin is shaken free from the cloths, melted, and run into 
barrels or tierces while warm. The hardness of this material 
depends on the quality of the stock from which it is derived 
and also on the amount of pressure to which the tallow is 
subjected. In general, it will have a titer of 46° or 47° C. 
This material, like tallow, is purchased on the result of the titer 
test. Tallow stearin finds utility in the currying and finishing 
of leather and in the candle industry and at times is used in the 
manufacture of high-grade soaps. 

43. Bleached Tallow Stearin. — In order to obtain 
bleached tallow stearin, it is simply necessary to bleach the 
foregoing product to a white color with the required amount 



30 PACKING-HOUSE INDUSTRIES, PART 2 

of fullers' earth. The bleaching is done in the usual manner, no 
notable quantity of fullers' earth being required to produce the 
desired white bleach. The industrial uses of this product are 
the same as for the ordinary tallow stearin, which is not usually 
bleached unless required for special trade; it is then always 
sold at a corresponding advance in price. 

44. BleacMng of Oils. — The bleaching of oils is carried 
out in the same manner as that of lard. With lard and tallow 
oils, however, the process need not be so carefully conducted 
with respect to temperature, etc. 

The temperature required for obtaining the requisite bleach 
in oils is higher than that required for lard and tallows. But 
here, also, the lower the degree of heat at which the oils may 
be made to bleach the better will be the odor of the product. 
As these oils are not used for food purposes, the taste and odor 
are not of so much importance as with lard, and the use of an 
excess of fullers' earth in bleaching is not so closely observed 
except as a matter of cost. 

The quantity of fullers' earth necessary to bleach a given 
oil varies with the nature of the material. While one oil will 
bleach with 2 or 3 per cent, of fullers' earth, another similar 
oil may require 7 or 8 per cent. When more than the latter 
quantity is necessary, as shown by preliminary tests, bleaching 
is not attempted, as the increased value of the bleached oil 
would not equal the cost of the labor and fullers' earth used 
in the operation. 

45. Bleaclimg Test. — The oils may be tested for the 
amount of fullers' earth necessary to bleach by taking an 
ordinary 4-ounce, oil-sample bottle and weighing in 100 grams 
of the oil under consideration. The percentage of fullers' 
earth judged necessary to effect the bleach is weighed off 
and then added to the hot oil in the bottle. By placing the 
oil and bottle in a steam bath for several minutes previous 
to adding the fullers' earth, a temperature closely approx- 
imating that obtained in the bleaching tank is obtained. If 
necessary, the temperature of the oil, which must be at least 
170° F., may be tested with a thermometer. 



PACKING^HOUSE INDUSTRIES, PART 2 31 

After adding the fullers' earth, the bottle is closed and 
violently shaken for 3 or 4 minutes to effect the bleach. The 
mixture is then poured on a filter paper placed in a hot funnel, 
and the color of the filtered oil observed. If not satisfactory, 
another test is made, using a larger quantity of fullers' earth. 
In this way, the amount necessary for the quantity of oil can 
be determined before starting to bleach. It should be remem- 
bered, however, that this test is crude and only comparative, 
as the conditions are not the same in the bottle as in the bleach- 
ing tank with the air-blower agitation. An oil will always be 
bleached in the tank with a smaller quantity of fullers' earth — 
approximately from 1 to IJ per cent, less — owing to the better 
agitation and more intimate and continuous contact between 
the fullers' earth and the oil. 

46. In bleaching oils the same precaution as with lard 
must be observed — that is, to have all moisture eliminated 
before adding fullers' earth — or no bleach will be obtained. 
After the bleached oil oozes from the filter press in a bright, 
sparkling condition unlike lard, it is run to a cooler, or tank, 
where it is allowed to cool to room temperature before being 
drawn into barrels. 

The apparatus shown in Fig. 5, Packing-House Industries^ 
Part 1, is used in the bleaching of oils. After low-grade oils 
have passed through the apparatus everything with which it 
has come in contact must be thoroughly cleaned so as to remove 
all traces of free acid and odor. 



BEEF EXTRACT 

47. In the making of beef extract in the packing house, 
the product of beef only is used. Beef extract is a very 
profitable product, as in most cases waste liquors, wash- 
ings and waters from the boiling of meat, which are 
practically without value for other piirposes, can be used to 
advantage. 

392—7 



32 PACKING-HOUSE INDUSTRIES, PART 2 

The National Formulary of the American Pharmaceutical 
Association has the following description of beef extract and 
tests for its purity : 

Beef extract is the residue obtained from fresh beef broth by evapora- 
tion at a low temperature. 

A yellowish-brown to dark-brown, slightly acid, pasty mass having an 
agreeable meat-like odor and taste. 

Twenty-five grams of extract of beef, diluted to 250 mils* with 
distilled water, yields a solution almost clear and free from sediment. 
Separate portions of this solution respond to the following tests : 

Boil 10 mils of the solution for 1 minute with 1.5 grams of purified 
animal charcoal ; add distilled water to replace that lost by evaporation 
and filter ; the filtrate produces no blue coloration when 1 drop is added 
to 3 drops of a solution of diphenylamine (1-100) in concentrated sul- 
phuric acid (nitrate). 

Distribute 10 mils of the solution over dry sand or asbestos and dry 
to constant weight in a flat-bottomed porcelain dish in an oven at a 
temperature of 105° C. ; it yields a residue of not less than .75 gram 
equivalent to 75 per cent, of solids in the original extract. 

Incinerate the residue from 10 mils of the solution obtained in the 
preceding test; the ash does not exceed 30 per cent, of the residue nor 
does the sodium chloride in the ash exceed 10 per cent, of the residue when 
determined as directed under the assay for chlorides. 

The manufacture of meat extract as carried on in the pack- 
ing houses and the meat-canning establishments of the United 
States is merely a side issue, and comprises essentially only 
the concentration of suitable meat juices to a proper consistency. 
Only on rare occasions is fresh meat used especially for meat- 
extract purposes and. even then it is only head meat or cheek 
meat, hearts, and other cheap meats, and these only when 
sausage meat is a drug on the market. 

For a short period some packers that make sausages on a 
large scale thought it profitable to soak all their sausage meat 
thoroughly, press the juice from the meat, and use this juice 
for meat extract. While they found this profitable for the 
extract department, it was greatly to the detriment of the 
sausage department. Sausages made of such extracted meat 
have a very fiat taste and no keeping qualities. 

The so-called cellar waters in which fresh meats have been 
soaked, the waters from the cooking or scalding of meats for 



A mil is equivalent to 1 cubic centimeter. 



PACKTNG-HOUSE INDUSTRIES, PART 2 33 

canning, and certain bone liquors, hereafter described, con- 
stitute the main sources of beef extract. The entire manu- 
facture from such Hquors is quite simple and relatively inex- 
pensive, the cost being practically the labor and steam em- 
ployed. Figs. 6 and 7 illustrate the apparatus used in the 
manufacture and show the principle of the operations. 

Beef extract is described by the regulations of the Bureau 
of Animal Industry as follows : 

Such terms as "meat extract" or "extract of beef," without qualifica- 
tion, shall not be permitted on the labels in connection with products 
prepared from organs or parts of the carcass other than fresh flesh. Ex- 
tract prepared entirely from parts of the carcass other than fresh flesh 
shall not be labeled "meat extract," but may be properly labeled with 
the true names of the parts from which prepared, as, for example, "liver 
extract." The term "beef extract " and "extract of beef " without qualifi- 
cation shall be applied only to extracts of fresh beef. Extract of cured 
beef or of other cured meat shall be designated respectively as "extract 
of cured beef," "extract of cured meat" or "cured-meat extract." In 
the latter case "cured" and "meat" shall appear on one line in the same 
style and size of lettering and shall be connected by a hyphen. When 
beef extract is mixed with extract from cured meat or extract derived 
from other parts of the carcass, such mixtures shall be designated as 
"compound meat extract," and, in addition, there shall appear on the 
label a statement showing the ingredients other than fresh flesh, which 
have been used in preparing the extract. In the case of fluid extract the 
word "fluid" shall also appear on the label, as, ior example, "fluid extract 
of beef." The word "fluid" merely indicates a lower percentage of sohd 
matter. 

48. The system of making meat extract by soaking the 
fresh meat with a relatively small amount of water and then 
pressing the juice from the meat with powerful hydraulic 
presses, is operated in the United States by only one small 
concern to a very limited extent. If prepared with the greatest 
care, a great deal of skill and experience, and in the very best 
obtainable vacutmi (of about 29 inches barometric pressure, 
at a temperature below 120° F.), requiring a special and ex- 
pensive vacuum pan, this meat-juice extract represents a very 
superior article and brings a high price, but the market is very 
limited. This process is too expensive to be employed in the 
ordinary meat-canning or packing establishments. 



34 PACKING-HOUSE INDUSTRIES, PART 2 

49. Process of Manufacture of Beef Extract. — The 

method of manufacturing beef extract from meat liquors, etc., 
is carried out in the following manner : 

The scalding liquors (soup waters) from the cook room 
of the canning department, bone liquors, etc., are pimiped 
into the wooden vat A, Fig. 6, which is about 2 feet high and 




Fig. 6 



of smtable length and width to hold 1 day's soup liquors, etc. 
Steel vats are also used for this purpose. 

Instead of using one very large tank, it is advisable to use 
two or three smaller ones. The tank or tanks are provided 
with 1-inch steam pipes that are placed sufficiently far apart 
to permit the pipes and the bottom of the vat beneath them 
to be readily cleaned. The tanks are slightly inclined toward 
one corner to facilitate complete draining and washing out. 



PACKING-HOUSE INDUSTRIES, PART 2 



v*)."^ 



The soup liquors and bone liquors are boiled down in tank 
A to about J or -J- their original volume. Then an equal volume 
(or about) of cellar water (from the soaking of fresh meat) 
is pimiped into the soup water. By continued heating of the 
mixture the albimiin in the cellar water is coagulated, and 
while coagulating envelops all the suspended impurities, defi- 
brinated blood can be used to accomplish the same result. 
Steam is turned off and the liquor is allowed to settle. The 
amber-colored clear liquor is drawn from vat A through cock 
c and the hair sieve d into the vat B which is arranged similar 
to vat A. In vat B the liquor is further concentrated to a 
density of about 7° or 8° Baume. If the liquor shows any 
tendency to become cloudy or off -colored a little more cellar 
water is added to it, thus producing a second coagulation and 
clarification of the liquor. Steam is then shut off from vat B 
and the liquor is drawn through cock e and the valves / into 
filter bags g. These bags are made of cotton flannel (about 15 
inches square on top and 2 feet deep) and are suspended by 
hangers h from a suitable rack. The gutter / catches the clear, 
filtered liquor and conveys it to the rotary evaporator. 

It is entirely practical to use filter presses instead of bags 
if the amount of liquor is sufficiently large. 

50. The rotary evaporator, Fig. 7, consists of a steam- 
heated, revolving drum n that is driven by a belt from the 
pulley 0. This drum, which is about 3 feet in diameter and 
from 5 to 10 feet long, revolves in a trough I that is supported 
by the legs m. At the back of the steam-heated roller n and at 
its side, scrapers, which serve to keep the surface clean, are 
arranged. In addition, the entire roller is supported in a frame 
that permits the raising and lowering of the roller according 
to the amount of liquor present. 

The amount of liquor in the trough / is so regulated that 
the drum n dips into it only to about the depth shown by the 
dotted line r. The steam drum is so constructed as to with- 
stand a considerable boiler pressure, but it is usually run 
with not more than a pressure of 20 pounds per square inch, 
and very frequently with less. In its revolutions (about 25 



Z6 PACKING-HOUSE INDUSTRIES, PART 2 

to 40 per minute), the drum carries sufficient liquor on its 
surface to prevent complete drying and burning. When the 
desired density is reached, which is about 20° Baume for the 
fluid extract and 32° Baiune for the so-called solid, or paste, 
extract, the concentrated liquor is drawn through cock q or 
dipped over the edge of the trough / into suitable receptacles, 
from which it is filled into bottles or jars. Such is the principle 
of the most simple and inexpensive and yet convenient meat- 
extract apparatus in operation. 




Fig. 7 

51. However, simply because better evaporators are 
offered in the different multiple-effect evaporators, the larger 
packing houses and many others have abandoned the use of 
roller evaporators. But these multiple-effect evaporators are 
only suitable for operations on a large scale when from 10,000 
to 50,000 gallons of meat liquors is concentrated in 24 hours. 
For a small concern the labor and attention demanded by 
these evaporators require too great an expenditure, and thus 
overcome their principal advantage — the saving in fuel. 

A rotary evaporator will evaporate for each pound of steam 
delivered to the apparatus about 1^- to 1} pounds of water, 
thus getting an evaporation of about 10 pounds of water 
from each pound of coal. The average double-effect evapora- 



PACKING-HOUSE INDUSTRIES, PART 2 Z7 

tors give 16 pounds of water evaporation for each pound of 
coal of the same class; the triple-effect evaporators give 24 
pounds of evaporation. The rotary evaporator is very suitable 
for the concentration of tank liquors or tank waters on a small 
scale and is used for this purpose by some packers. 

Small single-effect vacuum evaporators are made for handling 
extract in small plants. 

In making extract in an evaporator of this type it is neces- 
sary to finish the product in small vacuum kettles. The 
diluted liquors are concentrated for the evaporators in open 
boiling tanks in the same manner as for the rotary evaporators. 

52. Soup Liquors and Rib Bones. — ^For making meat 
extract the cooking and scalding waters of fresh meat and the 
cellar waters {soak waters from fresh meat) can be used if they 
are sweet and in sound condition. Cured-beef extract is made 
from corned-beef and other soup waters. 

All canning bones, that is, bones from meats cut for can- 
ning, thigh bones, etc., give, when heated for 1 or 2 hours 
with lukewarm water (about 165° F.), a bone liquor that is 
extremely well adapted as an addition to the soup liquors in 
the manufacture of meat extracts. Care must be taken, 
however, not to use the water too long or too hot on the bones, 
as in such a case the liquor will dissolve too much gelatine 
and give to the meat extract a gluey flavor. For the same 
reasons, bone liquors alone do not make meat extract, but 
when blended with soup liquors and cellar waters an excellent 
beef extract results. 

Where large quantities of cheap meat are available for 
beef-extract purposes, such, for example, as hearts, cheek 
meat, etc., the meat is cut into small pieces — about 1-inch 
cubes or thereabouts. This meat is then soaked in ice-cold 
water for 24 hours, the mass being frequently stirred with 
forks. After 24 hours the first water is drawn off and pimiped 
into tank Ay Fig. 6. Then a second quantity of water is put 
on for another 24 hours, this water also being sent to tank A. 
In former times hydrochloric acid in the proportion of 1 gallon 
of acid to 250 gallons of water was added to this water so as 

I L T 321—8 



38 PACKING-HOUSE INDUSTRIES, PART 2 

to get a better yield; but, according to a decision of the Secre- 
tary of Agriculture, hydrochloric acid can no longer be used in 
the manufacture of meat extract. 

The cold, extracted meat is then sent to the cook room 
where it is cooked for from 3 to 4 hours in the scalding tubs, 
or for 2 hours in iron digesters at a steam pressure of 20 pounds 
per square inch. The residue of this cooking either goes into 
the tankage or is occasionally sold for dog biscuit and other 
similar purposes ; at times it is worked into mince meat. 

53. All the apparatus used in the manufacture of meat 
extract must be thoroughly cleaned every day. The tanks A 
and B, Fig. 6, must also be kept scrupulously clean not only 
at the sides and bottoms but especially around the steam 
pipes. Occasional boiling with soda-ash solution will clean 
these vats perfectly. The coagulum from these vats, which 
collects in the sieve d and the filter bags, finds proper use in 
the tankage. The filter bags must be thoroughly cleaned 
with hot water after each day's use. Occasionally it happens 
that the liquid in the rotary evaporator turns cloudy because 
of imperfect previous clarification. In such cases the liquid 
is conveyed into a steam- jacketed open kettle where either 
fresh cellar water or defibrinated blood is added and the mass 
brought to a boil, producing a new coagulation; then by 
filtration through the bags a perfect clarification of the material 
is obtained. 

54. rorms of Extract. — Beef extract is put on the 
market in two forms, either as fluid extract or as paste extract, 
according to the degree of concentration. 

55. Fluid extract is concentrated to a density of about 
29° to 32° Baume, and contains from 42 to 48 per cent, of 
moisture. As a rule, there is an extra amount of common 
salt added, so as to bring the percentage of salt up to 10 per 
cent. This requires usually from 2 to 4 per cent., as the meat 
from which the extract is made furnishes from 6 to 8 per cent, 
of salt. The extra amount of salt in the fluid extract is neces- 
sary to give it better keeping qualities, as no antiseptics or 



PACKING-HOUSE INDUSTRIES, PART 2 39 

preservatives are ever used in beef extracts. Fluid extract is 
usually put up for the trade in glass-stoppered bottles; large 
quantities for storing, etc., are put up in square, 14-pound, 
meat-canning tins, the cans being processed in dry steam for 
1 J hours at a pressure of 10 pounds per square inch. 

56. Paste extract is boiled down to a concentration so 
that the product contains from 20 to 24 per cent, of moisture; 
it then contains from 55 to 65 per cent, of organic substances 
and from 8 to 10 per cent, of salt. Paste extract is usually 
put up for the trade in porcelain or milky-glass jars; but to 
store or ship in large quantities it is put up in square, 14- 
pound cans and capped without any processing. 

Fresh meat such as roast beef, etc., prepared for canning 
purposes in the regular way yields about 1 pound of paste 
extract from 60 pounds of meat (from soup water and cellar 
water). By longer scalding in the preparation for canning 
the yield can be raised to 1 pound of paste extract from 40 
pounds of meat. If the meat is treated only for extract, that 
is, if the meat is finely cut, soaked for 24 hours, and cooked 
to thorough disintegration during 3 or 4 hours, the yield will 
be about 1 pound of paste extract from 25 to 30 pounds of 
meat. Bone liquors give i to | per cent, of paste from the 
amount of bones soaked in warm water. 

The labor in the beef -extract department (exclusive of the 
label room) does not amount to much, one man and a helper 
being able to produce large quantities of extract. 



MEAT CANNING 

57. The hermetic sealing of food, usually referred to as 
canning, is an industry that has grown to be an important 
factor in the commercial and industrial development of the 
United States. This industry has long since passed the experi- 
mental stage and has taken its place among the leading indus- 
tries of the country. 

The process used in the canning of meats is what is known 
as the Appert process, which was invented in 1809. Although 



40 PACKING-HOUSE INDUSTRIES, PART 2 

this process has been well known to scientists ever since its 
invention, its commercial application has been available only 
a comparatively few years. Up to the present time nothing 
has been discovered to supersede this universally applied 
process for the canning of meats and of vegetables. 

58. Prior to 1795, drying and the use of salt and sugar 
were the only methods used to any extent in the preserva- 
tion of foods. At this time, Nicholas Appert, a Frenchman, 
who had spent most of his life in the preparation and preser- 
vation of articles of food, being stimulated in his work by the 
offer of a reward by the French Navy Department for a method 
of preservation of foods for sea service, submitted to his govern- 
ment an exhaustive treatise bearing on the hermetic sealing of 
all kinds of food. His method was to enclose fruit in a glass 
jar, which was then corked and subjected to the action of 
boiling water for a time, which varied with the article treated. 

A description of his process can best be simimed up in his 
own words, as follows: *Tt is obvious that this new method 
of preserving animal and vegetable substances proceeds from 
the simple principle of applying heat to the several substances 
after having deprived them as much as possible of all contact 
with the external air. It might, on the first view of the sub- 
ject, be thought that a substance, either raw or previously 
acted on by fire and afterwards put into hot bottles, might, 
if a vacuum were made in those bottles and they were com- 
pletely corked, be preserved equally well with the application 
of heat in the water bath. This would be an error for all trials 
I have made convince me that the absolute privation of the 
contact of external air (the internal air being rendered of no 
effect by the action of heat) and the application of heat by means 
of the water bath, are both indispensable to the complete 
preservation of alimentary substances." 

As before mentioned, time has proved Appert's method 
to be the most satisfactory for preserving food in its natural 
state. 

59. Glass jars, which were originally used for this pur- 
pose, were gradually abandoned, as it was found that they 



PACKING-HOUSE INDUSTRIES, PART 2 41 

could not withstand the extremes of temperattires, and that 
they were expensive, bulky, and costly in transportation. 
Although glass jars are used to some extent at the present 
day for the preserving of vegetables, fruit, etc., tin cans are 
universally employed for the canning of meat. 

The objection having been urged against the use of tin 
cans that the natural acids of fruits, vegetables, meats, and 
fish act on the tin and solder in such a way as to form metallic 
salts or metallic compounds that are injurious to the health, 
the matter was carefully investigated by expert chemists, 
who reported that the objection is groundless if good tin is 
used. In the poorer grades of tin, injurious substances were 
found, but in such small quantities that they were negligible. 

The principle underlying the preservation of meat or other 
edible substances in air-tight cans is that the decay of organic 
matter is not due alone to oxidation, but to the action of 
bacteria, organisms, ferments, etc., which attack and act on 
the organic substances, decomposing them and resolving them 
into their original elements or other compounds. The heating 
of the meat or other material in the process of canning destroys 
or paralyzes the bacteria and ferments, and the hermetic seal- 
ing of. the cans prevents bacteria from again entering into the 
material. Hence, canned goods made of good material and 
properly prepared remain unchanged and in good condition 
indefinitely. The process is, in fact, one of sterilization by 
heat. 

60. The meat-canning industry, in connection with the 
packing industry was started in a small way in Chicago about 
the year 1877. It was primarily estabHshed with a view of 
saving a large proportion of the meat that up to that time 
had been either unsalable or of very little value. 

The canning industry comprises so many different branches 
that only the most important features and the general plan 
and scope followed will be given here. 

61. Selection and Preparation of the Meat. — The 

meat selected for canning is ordinarily taken from lean cattle 
in good, healthy condition, which are not suitable for beef 



42 



PACKING-HOUSE INDUSTRIES, PART 2 



cattle. Cattle of this kind are known in the trade as canners. 
These animals are slaughtered largely to obtain meat for canning 
purposes. The parts of the beef that cannot be sold at a profit 
go to the canning department of the establishment. The hind 
quarters, loins, and, in some cases, salable fore quarters are 

sold in the fresh state. 
The fore quarter, however, 
furnishes the bulk of the 
meat for canning purposes. 
One reason for this is that 
there is less fat on this part 
of the animal. 

The fore quarter is taken 
to the boning room, and 
the bones are removed en- 
tirely from the meat. This 
meat is cut into pieces of 
about 5 or 6 pounds each, 
in order to facilitate curing 
uniformly throughout 
when placed in pickle for 
the making of corned beef. 
Great care is exercised not 
to leave even small bones 
in the meat, as they are 
liable to break the stuffing 
machine and otherwise 
cause delay by stopping 
this machine when the 
meat is being stuffed into 
cans. The small pieces of 
meat are cured by themselves and mixed with the larger ones 
when canning. 




Fig. 8 



62. Curing^ and Cooking tlie Meat. — The meat is cured 
in a mild pickle in which are placed small quantities of salt- 
peter and sugar, the former not exceeding 4 ounces to each 
100 pounds of meat, and the latter varying in quantity from 



PACKING-HOUSE INDUSTRIES, PART 2 43 

1 to 2 per cent. The meat after remaining in this pickle from 
15 to 26 days is ciired and ready for boiling or shrinking. After 
washing in cold water to remove the pickle, the meat is placed 
into boiling vats. These are wood-end vats that hold at each 
charge about 700 pounds of meat. The time of cooking varies 
with different meats. For canned roast beef the meat is not 
subjected to the curing process, but is cooked while fresh in 
boiling water for 20 minutes. The cooked meat is then removed 
and stuffed into cans by the can-stuffing machine, shown in 
Fig. 8, after the requisite amount has been weighed off. In 
canning the meat suffers considerable shrinkage in weight 
averaging about 20 per cent, with roast beef. 




For cooking corned beef the meat is boiled for 10 minutes, 
after which it is allowed to stand in the hot water for 1 hour. 
This method freshens the meat and also causes far less shrink- 
age than by another common method of boiling it for 1 hour. 
The average shrinkage in cooking corned beef is about 38 per 
cent., although at times it is not more than 30 per cent. The 
soup water from the cooking or shrinking of meats is used for 
making soups and also in the manufacture of beef extract. 

63. Canning and Processing. — ^When the meat is 
removed from the cooking tubs it goes to the cutting table, 
where it is cut into sizes suitable for the stuffing machine; it 



44 



PACKING-HOUSE INDUSTRIES, PART 2 



is then passed to the weighing table where the proper amounts 
are weighed off and fed to the stuffing machine. After the cans 
are stuffed they are reweighed, wiped, the cap placed over the 
opening through which the meat was stuffed, and inspected. 
The cap is soldered on when the can is on the capping machine 
shown in Fig. 9. The meat is then ready to be processed, or 
cooked in the can, by one of the three methods which follow: 




Fig. 10 



64. In the boillng-off process, after going through the 
capping machine the small hole in the center of the cap, the 
vent, is finally closed with solder, when the can is ready for the 
first of the two cookings necessary in this process. This may 
be done either in a water bath or in a retort like that shown in 
Fig. 10, the retort or steam process being most commonly 
used. 

The retort shown in Fig. 10 is 28 inches wide, 32 inches 
high, and lOj feet long, and will hold at one time 700 three- 
pound cans when arranged on the iron trays as shown in the 



PACKING-HOUSE INDUSTRIES, PART 2 45 

illustration. The retort is provided with steam connections 
and a steam gauge for registering the steam pressure. Doors 
are located at each end and are provided with the usual tighten- 
ing appliances. There is always a valve controlling the exhaust 
of the retort, as with some goods and in boiling off sealed cans 
the exhaust has to be kept open. The retort has a perforated 
steam-pipe fastened to the entire length of the bottom so as 
to distribute the steam equally throughout the box when 
processing. 

Different materials are subjected to different pressures of 
steam and remain in the retort for different periods of time. 
The size of the cans also influences the time and pressure. 

65. The object of processing, as mentioned before, is for 
complete and thorough sterilization as well as for additional 
cooking of the meat. At the expiration of the required time 
in the retort, the cans are removed on the trays and then in 
order to allow the air in them to escape, they are punctured. 
This operation is done as quickly as possible, the vents closed 
up, and the cans returned to the retort and heated again for 
a shorter or longer time, depending on the size of the can. This 
latter processing is technically termed boiling off. 

Processing and boiling off under water with closed vents 
is also practiced extensively with satisfactory results and it 
is claimed by some that this method gives a better flavor to 
the canned product. In processing in the water bath, the 
time of process is taken from the time the water begins to 
boil. These process tanks, either of wood or iron, are 3 feet 
10 inches long, 2 feet 10 inches wide, and 3 feet 6 inches deep. 
The cans are put into the process tanks on trays to facilitate 
handling in removing. The cans, when removed, are also 
punctured the same as in steam processing, sealed, and boiled 
off again in the water. 

The calcium-chloride bath .is also employed for processing 
and boiling off. A solution of this salt is made with water, 
which makes possible a temperature of 240° F. in the open 
bath, whereas the highest temperature obtainable in the 
ordinary open vat with water is 212° F. The final treatment of 



46 



PACKING-HOUSE INDUSTRIES, PART 2 



the cans after processing is the same in all three methods and 
will be described later. 

66. In the cold vacuum process, the cans after being 
capped are first conducted by a belt conveyer to the soldering 
machine where the vent is closed. This machine is illustrated 
in Fig. 11. 

The cans are placed in the machine through the door A and 




Fig. 11 

a vacuum is then made inside the machine. The machine is 
then revolved by hand and the cans are soldered with one 
turn of the machine. After this operation the door is opened 
and the cans are removed by one more turn of the revolving 
plate, which is operated by the turning wheel B. These 
vacuimi sealing machines are equipped for either electric or gas 
soldering. 



PACKING-HOUSE INDUSTRIES, PART 2 47 

After sealing, the cans enter the retort and steam under 
suitable pressure admitted. This pressure may vary from 2 to 
12 pounds and the time of application from | hour to 12 hours, 
depending on the size of the can and the nature of its contents. 
The subsequent steps are common to all three methods. 

67. In the hot process, after being packed and capped, 
with the vent hole open, the cans are passed through a steam 
box. The object of this procedure is to remove the air remain- 
ing in the container. The vent is immediately closed to prevent 
reentering of the air which hinders the processing as carried out 
in the foregoing method. 

The final step in all three methods after removal from the 
retorts or process tanks for the last time consists in taking the 
cans to the shower room, where cold water is run on them until 
they are cool. This sudden chilling contracts the ends of the 
cans, making them slightly concave, which is the proper con- 
dition for canned goods. The cans to remove any grease or 
other accumulations are then sent through a washing trough 
by mechanical means. From the washing machine the cans 
go to the lacquering and labeling room where they are fiaished 
and made ready for packing and shipping. 

68. The following specifications of the United States Navy 
are of interest in showing the care taken in the packing house 
in the preparation of food products : 

CORNED BEEF, COOKED AND TINNED 

Meat to be of the first quality cooked corned beef; no meat other than 
from the dressed carcasses of well-nourished cattle to be used. Meat to be 
strictly fresh and in prime condition. Head meat, scrap meat, and meat 
from shanks, flanks and skirts to be excluded. The finished product to be 
free from gristle, blood clots, excessive fats, and fatty connective tissue, 
and excessive jelly. To be of good flavor and free from objectionable 
odors. Upon analysis the finished product to show not more than 33^ 
per cent, of common salt and not more than .2 per cent, saltpeter. 

TINNED HAM 

Shall be of the best quality boneless ham, fuU weight, in key-opening 
tins of 2 pounds each, weight of tins not included. Each tin to be marked 
with contents, name of contractor, name of packer, brand, and date of 
392—8 



48 PACKING-HOUSE INDUSTRIES, PART 2 

packing, and to be properly lacquered. Each dozen tins to be enclosed 
in a substantial box made of well-seasoned pine or spruce, properly nailed; 
sides to be f " and ends 1" thick. Boxes to be marked on one end with 
contents, name of contractor, date of packing, and the stamp provided 
for inspected meats by the Secretary of Agriculture, and to be free from 
all other marks. 

The contractor shaU guarantee that the ham will keep good in any 
climate for 1 year from date of delivery. 

TINNED BACON 

To be dry salt-cured, cut from 10-pound average bellies when laid down; 
square cut, seedless; from light prime hogs in good condition; sweet and 
sound; a good streak of lean in each piece; not too fat; less than 2|" 
thick at shoidder end; well cured. 

To be put up in fiat, rectangular, key-opening cans (vacuum process) 
of 5 pounds net weight each; tins to be marked with contents, name of 
contractor, and date of packing, and to be properly lacquered; 2, or at 
most 3, pieces of bacon of about equal weights (no scraps) to be put up 
in each can; the contents of each can to be wrapped in vegetable parch- 
ment paper. 

Tins to be enclosed in a substantial box, made of well-seasoned pine or 
spruce, properly nailed; the sides, tops, and bottoms to be made f" 
thick, and the ends to be 1" thick, when finished; each box to contain 8 
tins, and to be distinctly marked, on only one end, with contents (stating 
net weight), name of contractor, and date of packing. Each case must 
bear thereon the stamp provided for inspected meats by the Secretary of 
Agriculture. Cases must be free from advertising matter. 

The contractor shall guarantee that the bacon will keep good in any 
climate for 1 year from date of delivery. 

LARD 

To be made from absolutely fresh-killed properly chilled hogs. To 
contain only body and leaf fat (no head, foot, or gut fat to be used). 
To be white in color, without bleaching, agitation, use of chemicals, or 
any other means of artificial coloring. To be thoroughly cooked by 
steam heat. 

Lard to be chilled to a state of being liquid and then run into square 
tins of 5 pounds each, net. Tins to be hermetically sealed, with all seams 
soldered, and to be properly lacquered. Tins must be thoroughly cleaned 
before being packed into wooden cases. Each tin to be marked with con- 
tents, name of contractor, and date of packing. 

The contractor must furnish free of charge, with each delivery, a certifi- 
cate from a licensed produce-exchange inspector that the deliveries are 
what are required by the specifications in regard to quality of lard and 
packing. 



PACKING-HOUSE INDUSTRIES, PART 2 49 

The contractor shall guarantee that the lard will keep good in any climate 
for 1 year from the date of delivery. 

To be packed in boxes made of planed white pine or spruce; tops, 
bottoms, and sides to be |" thick; ends to be 1" thick, when finished. All 
cases to be strapped with |" flat iron, and distinctly marked, on one end 
only, with contents (giving net weight), name of contractor, and date of 
packing. Each case to contain 8 tins. Cases to be free from advertising 
matter. 



BUTTERINE 

69. Composition. — Butterine, or oleomargarine, is com- 
posed of oleo oil, cottonseed oil, peanut oil, coconut oil, 
genuine butter, and neutral lard, with a small proportion of 
moisture and salt, with or without coloring matter. 

The manufacture of this product is carried on in packing 
houses where state statutes permit its manufacture. The 
highest grades of butterine have as much as 33 per cent, of 
genuine butter in their composition and others 25 per cent. 
This proportion may be and is varied at will by the different 
manufacturers. Each manufacturer has his individual formula, 
but as every factory in the United States is under direct gov- 
ernment supervision, it is obvious that only materials of 
unquestioned healthfulness may be used. 

Each factory is required to make a daily report of the exact 
quantity and kind of materials used and also the number of 
pounds of butterine produced from these materials. This 
report must be made under oath to government officials, and 
severe penalties are incurred for infractions of the regulations. 

The manufacture is attended with the most scrupulous 
cleanliness not only as a matter of personal convenience, but 
as an essential in producing a merchantable article of trade, 
as without this cleanliness good butterine cannot be made. 

A federal statute vitally affecting the manufacture of oleo- 
margarine went into effect on July 1, 1902. This law imposes 
a tax of 10 cents per pound on oleomargarine, or butterine, 
used for domestic consumption, in which yellow coloring matter 
is introduced. The effect of this legislation has been to reduce 
considerably the number of establishments formerly engaged 



50 PACKING-HOUSE INDUSTRIES, PART 2 

in the manufacture of this article. For uncolored oleomar- 
garine, that is, butterine manufactured from the materials in 
their natural state and without being colored in imitation of 
butter, a federal tax of only | cent per pound is imposed. 

70. Ingredients Used. — As previously stated, the quality 
of the ingredients used in making butterine is of the highest. 
Their condition and preliminary treatment are as follows: 

The milk used is received in cans surrounded by felt casings 
to protect it from changes in temperature. This milk is poured 
into the receiving vat from which it is pumped through a fine 
strainer to remove all impurities, into the pasteurizer. Here 
it is heated to a temperature of 180° F., | hour, whereby all 
germ life and objectionable flavor is destroyed. 

The milk is then ripened, that is, it is caused to become sour 
or acquire acidity through the addition of certain lactic-acid- 
forming ferments. This process usually requires about 24 
hours at a temperature of 60° to 70° F. 

The neutral lard used for butterine does not have to be 
grained, as it is used in a liquid condition. The same applies 
with equal force to the oleo oil. 

The cottonseed oil used is of the grade known as butter oil — 
the choicest grade of this material. 

The peanut and coconut oils are highly refined and de- 
odorized and are of the highest grade obtainable. 

71. Clmrning: and Finishing. — The chums used for 
producing butterine are fixed, upright, sheet-iron cylinders 
capable of holding a charge of about 600 pounds of mixed 
material. The churns are partly enclosed on the top with 
curved sheet iron and inside the churn are paddles fixed to a 
revolving shaft. When churning, this shaft with the paddles 
makes from 500 to 600 revolutions per minute. 

The proportions of the different ingredients vary. The 
following proportions for 100 pounds of butterine are those 
used by a manufacturer who makes about 15 tons of butterine 
daily. 

Cream sufficient to produce 15 pounds of butter; cotton- 
seed oil, 15 pounds; neutral lard, 35 pounds; and oleo oil, 



PACKING-HOUSE INDUSTRIES, PART 2 51 

35 pounds. The proportion of butter color varies with the 
season and the trade; from | to 1 ounce per 100 pounds of 
butterine is the usual amount added. This is placed in the 
churn with the other ingredients at the time of churning 
when colored oleomargarine is desired. Otherwise, the proc- 
ess is carried out as described without the use of coloring 
matter. 

The coloring matters that may be used at the present time 
in coloring butterine, are annatto (see Organic Chemistry) and 
the colors technically known as Yellow A.B. and O.B. These 
must be prepared according to the regulations of the United 
States Department of Agriculture. 

72, The desired weights of the various ingredients are 
run into the churn and the mixture is churned by means of 
the revolving paddles for 6 or 7 minutes, when the operation 
is completed. The best temperature for churning is about 
90° F., and the various ingredients are introduced into the 
chum at temperatures to obtain this. The oleo oil and 
neutral lard are run in at about 110° F., the cream at 
about 70° F., and the cottonseed oil at normal room tem- 
perature. 

The butterine is now run from the bottom of the churn 
into tanks, or vats, of ice-cold water to produce the requisite 
butter grain. This water is kept cold by having a constant 
supply of ice in it. Some manufacturers place cakes of ice 
in the bottom of the vats over which the water flows con- 
stantly, thus maintaining a steady temperature of about 
34° F. The churned product is allowed to remain in these 
vats with the water for about 10 minutes, or until it has 
acquired a firm set, when it is thrown by means of wooden 
shovels on inclined tables and permitted to drain. The tem- 
perature of this room is kept at 70° F. At this stage the but- 
terine is salted with an amount varying with the requirements 
of the trade. From i to f ounce of salt to 1 pound of butterine 
is sprinkled over the mass which during the 10-hour period of 
draining is turned over three or four times to allow the water 
to drain from it. 



52 PACKING-HOUSE INDUSTRIES, PART 2 

This is generally done at night so that the material is ready 
for working the next day, when the butterine is worked with 
the regulation butter worker, to press out the superfluous 
water and to distribute the salt evenly. Butterine is packed 
in regulation butter tubs, on every package of which is placed 
the usual revenue stamp and a penalty label. It is also made 
into pound prints resembling butter and wrapped similarly in 
parchment paper. Very little labor is attached to the making 
of butterine, a few employes being able to produce large quan- 
tities daily. 

In the United States, the names butterine and oleomargarine 
are used synonymously. In Europe, however, oleomargarine 
is almost always termed margarine. 

Within the last few years the manufacture of the so-called 
nut margarine has asstmied rapidly increasing proportions. 
The name is due to the fact that it contains coconut and 
peanut oils to the exclusion of all other fats excepting those 
contained in the milk. The method of manufacture parallels 
that of the regular oleomargarine. 



GLUE 

73. Glues are now made in many packing houses from 
raw material that was at one time sold to glue manufacturers 
and from liquors that were formerly wasted. While perhaps 
not properly belonging to the packing industry, nevertheless 
a short account of the method of making glue will be given 
here. 

The chief soiurces of glue in the packing house are the waters 
or liquors from the boiling of cattle and sheep heads, feet, and 
bones, and those from sinews, hide trimmings, horn piths, 
calves* heads, and pigs' feet. In making glue, a thorough 
knowledge of the raw material is necessary in order to produce 
good results. In this manufacture as in all others, poor material 
will never yield a high-grade, finished product. Material in 
prime condition if allowed to lie around in heaps or be subjected 
to incipient decomposition will very quickly become unfit for 



PACKING-HOUSE INDUSTRIES, PART 2 53 

use as glue ; or if used, will produce only low-grade, weak, and 
foul-smelling glues. To obtain good glues, it is necessary to 
have the stock in a sound, sweet condition. 

74. Glue Stock. — The glue stock may be either green 
or dry, green-salted or dry-salted. Green stock consists of 
material in the fresh state, such as fresh hide pieces, sinews, 
calves' heads, feet, etc. Dry stock consists of glue-making 
material such as bones, etc., dried, without salting or other 
treatment. Green-salted material comprises fresh stock that 
has been cured by means of salt, such as pieces of salted hides, 
sinews, calves' trimmings, etc. Dry-salted goods consist of 
trimmings, etc., from South American hides, rawhides, etc. 

75. In examining glue stock for utility, the examination 
should include, for dry and dry-salted stock, the gain in weight 
by soaking over night in water. This should be about 50 per 
cent, of their original weight and, in addition, the soaked 
pieces should be tough and of firm texture. The odor of both 
the soaked stock and the water should not be strong. If such 
is the case, the stock is moldy or the gelatinous matter has been 
destroyed by insects. The impurities, consisting of dirt and 
salt, should not exceed 5 or 6 per cent. 

Green-salted stock should be examined for the purpose of 
determining whether it contains any decomposed, discolored, 
slimy, or heated pieces. The latter, if not in a state of 
decomposition, are bordering on it. The total amount of 
salt and moisture for this material should not exceed 40 
per cent. 

The bones in the packing house designed for glue should 
not be overcooked; that is, they should be smooth and hard 
and not have a chalky, white surface. The latter condition 
indicates that most of the glue has already been cooked out 
of them. Soft bones, such as rib bones, yield more glue than 
the hard bones of the legs and thighs. Bones that have been 
exposed to weather influences were formerly supposed to yield 
only little glue of poor quality, but by a recently devised 
secret process these bones may be made to yield an excellent 
light-colored glue. 



54 PACKING-HOUSE INDUSTRIES, PART 2 

Horn piths should be free from the skin covering and should 
not be discolored from drying on steam coils. If the tips of 
the piths are easily broken off, it shows that they have been 
subjected to a very high temperature and much of the gelati- 
nous matter thereby destroyed. 

Fresh glue stock presents no difficulties in the manufacture 
of glue; but care must be taken to keep it from becoming 
decomposed before using. 

76. Bone Glue Liquor. — One of the chief products of 
the packing-house glue department is bone glue of which 
there are many qualities, varying from a fine white gelatine 
to dark-colored, low-grade glues. One method of preparing 
this product consists in cooking the bones in open vats and 
evaporating the resultant glue liquors to the desired density 
in the vacuum pan from which the liquors are run into the 
forms for cooling. As many cookings of bones for glue liquor 
are made as is practicable; that is, the bones are used as long 
as the liquors obtained contain sufficient glue to make evapora- 
tion profitable for forming the glue jelly. 

Another method of producing glue liquors is by cooking 
the bones under pressure. The same principle is applied as 
in other cases; such, for example, as cooking the bones in 
tanks under a pressure of 10 or 15 pounds per square inch 
for two periods of 2 hours each. The yield of glue by this 
method is better than that obtained from cooking the bones 
in open vats. By the pressure method, from 11 to 14 per 
cent, of glue is obtained, while the open cooking yields only 
from 6 to 10 per cent. When cooking the bones in the tanks 
under pressure water sufficient to cover them must be added. 

Bones are sometimes leached with acid to dissolve out the 
inorganic matter. For this purpose the bones should be as 
free as possible from grease and also tough and hard. The bones 
are covered with dilute hydrochloric acid. They remain covered 
generally from 3 to 4 weeks, depending on the size of the bones. 
The bones after this leaching are soft and spongy and have a 
rather strong odor. The material is then known as raw gelatine 
and is suitable for the best grades of bone glue and gelatines..- 



PACKING-HOUSE INDUSTRIES, PART 2 55 

The glue liquors while hot are run to the settling tanks 
where they are allowed to settle and clarify. Any grease 
appearing on the surface is carefully removed as it is impor- 
tant to have all glues as free as possible from grease. 

77. Horn-Pith. Glues and Gelatines. — In using horn 
piths for making glues and gelatines, they are leached with 
hydrochloric acid of 2° Baume or with phosphoric acid of 
6° Baume in vats having perforated false bottoms. When 
the horn pith can be cut through easily in any direction with 
a knife the leaching is finished. The horn piths are then 
drained free from acid which is replaced with clean, soft water 
until all traces of acid are removed. This material furnishes 
fine gelatines and glues on cooking. From 30 to 35 per cent, 
of raw gelatine may be obtained from dry horn piths ; and from 
the dry, raw gelatine, about 90 per cent, of glue. When phos- 
phoric acid is used for leaching from 6 to 8 weeks is required 
for leaching the horn piths. 

78. Head Glue Liquor. — The glue liquors from cook- 
ing heads and feet previously described yield on evaporation 
light, yellowish-colored glues, closely approaching white. The 
liquor when drawn off from the cooking vats has a density of 
about 2° Bairme. It is allowed to clarify by settling and is 
then evaporated in the vacuimi or other apparatus to the 
desired consistency when it is run into the jelly molds, cooled, 
cut, and dried in the usual way. 

79. Clarification of Glues. — When glue liquors are 
made of sound stock they come from the cooking vats in a 
clear condition and, on standing a few hours in the settlers 
become easily clarified, any impurities rising to the top with 
the grease or settling at the bottom. The glue liquor after 
settling is tested for clearness and, when in a satisfactory con- 
dition, is evaporated either in the vacuum pan or other ap- 
paratus and run into forms for glue jelly. 

The first runs of glue liquors in general are easy to manip- 
ulate, but the last runs containing the residual glue stock are 
us'ially muddy and contaminated with impurities. This class 



56 PACKING-HOUSE INDUSTRIES, PART 2 

of material is most frequently made into colored glues by- 
mixing zinc oxide with them, thus producing a good-looking, 
merchantable article. 

It is necessary for glues to have an acid reaction in order 
to clarify by settling. Where a neutral or alkaline condition 
exists it is better to clarify by sprinkling a solution of alum 
into the glue solution. Albumin is used at times as a clari- 
fying agent with good results. The glue liquor is cooled to 
about 140° F., when the solution of albumin is added and 
the whole stirred thoroughly and then heated just short of 
the boiling point. The albumin in coagulating entangles the 
impurities in the glue liquor and settles to the bottom. The 
addition of a small amount of ammonium chloride with the 
albumin makes the clarification more complete. 

During recent years in the clarification of glues the filter 
press has been brought into use. If a decolorizing material 
such as bone black is mixed with the glue liquors on pimiping 
the mixture through the filter press, a clear, brilliant, and 
somewhat bleached product is obtained. In many estab- 
lishments this method has superseded the old way of allowing 
the glue to clarify itself by settling on account of the time 
saved and the reduced liability in warm weather of the warm 
glue liquors becoming sour, or decomposed, and thus rendered 
useless. 

80. Bleaching Glue Liquors. — The bleaching of glue 
liquors is practiced a great deal by modern glue makers. 
Bones, before cooking, if covered with a 1-per-cent. solution 
of sulphurous acid for 24 hours, are bleached to a consider- 
able extent. Such bones are washed free from acid and when 
boiled furnish a very light-colored glue. 

A very common method of bleaching glue liquors is to pass 
washed sulphur-dioxide gas through them until the desired 
light color is obtained. This is the most common and the 
cheapest method of bleaching. Liquid sulphur dioxide is now 
manufactured for this purpose and is transported in heavy 
iron cylinders similar to those used for anhydrous ammonia. 
While the sulphur-dioxide method of bleaching is cheap, it 



PACKING-HOUSE INDUSTRIES, PART 2 57 

cannot always be used with good results on very dark-colored 
glue liquor. 

Other bleaching agents employed are zinc salts such as 
sulphate and chloride but, unless carefully used, their presence 
in the glue is liable to be very detrimental. 

In Germany limed glue stock is treated with hydrochloric 
acid and chloride of lime for about | hour, after which it is 
thoroughly washed. If this treatment is continued too long, 
however, the stock will become hard and almost insoluble. 
The so-called Cologne glues, which are very light-colored, 
are said to be produced by this treatment. 

Peroxide of hydrogen has been used for bleaching glues 
and answers the purpose well. It will almost instantly turn 
the darkest-brown glue liquors into a light-yellow color. The 
item of cost, however, has prevented this material from assimi- 
ing commercial importance. 

81, Preservatives Used in Glues. — Preservatives are 
frequently used in glues. Sulphur dioxide, in addition to 
bleaching glues, acts as a preservative for them. The preserva- 
tives most commonly employed are the zinc salts — the oxide, 
sulphate, or chloride. At the same time the sulphur dioxide 
has the additional advantage of producing a light-colored glue. 
Alum is also employed as a preservative, but it is liable to give 
a flaky appearance to the glues if used in too large quantities. 
Formaldehyde has recently been employed as a glue preserva- 
tive. If, however, an excess over and above that necessary for 
preservative purposes is added to glue liquor, the glue will 
almost immediately be rendered insoluble. 

82. Concentration of Glue Liquors. — Glue liquors may 
be concentrated by evaporating them in jacketed kettles, in 
evaporating vats provided with steam pipes, or by means of 
a revolving steam-heated drum similar to Fig. 7. With all 
these methods the evaporation takes place under ordinary 
atmospheric conditions. The results in many cases are very 
satisfactory, but all open evaporators have the disadvantage 
of subjecting the glue liquors to a high temperature which 
is very detrimental to the strength of the finished glue. With 



58 



PACKING-HOUSE INDUSTRIES, PART 2 



many of these evaporators the heated iron surface reaches a 
temperature of nearly 300° F., which natiirally scorches the 
glue, forms a crust on the heated surface, and thus hinders 
rapid evaporation. The glues produced by open evaporators do 
not compare favorably in strength and color with those made of 
the same kind of material by evaporation in a vacuum apparatus. 
The concentration of liquors in the vacuum apparatus is 




Fig. 12 

accomplished by producing a partial vacuimi in the apparatus, 
thus partly removing the atmospheric pressure from the 
liquid therein. By exhausting the air and producing a vacuimi 
of 8.7 pounds per square inch, as shown by the vacutim gauge, 
the liquor enclosed in the vacuum pan will boil at a temperature 
of 170.1° F. The lower the temperature at which any glue 
is made, the better will be its color and strength. This is 
especially true of high-grade glues. 



PACKING-HOUSE INDUSTRIES, PART 2 59 

83. Vacuum evaporators are operated either by direct 
steam or by exhaust steam from an engine. Another advan- 
tage in using this kind of apparatus is that less fuel is required 
for the evaporation of a given weight of water. In the ordinary 
vacuum pan, 1 pound of coal will evaporate upwards of 8 
pounds of water, while with open evaporators, excellent use 
is made of the coal if 1 pound evaporates 6 pounds of water. 
With a vacuum pan of three effects, or chambers, an evapora- 
tion of 24 pounds of water is obtained from 1 pound of coal. 
The economical principle of the multiple-effect vacuum pan 
consists in utilizing the heat over and over again. The steam 
introduced into the tubes of the first effect evaporates a quantity 
of water and the steam thus formed passes into the tubes of the 
second effect. The steam produced by this evaporation passes 
into the third effect and evaporates still more water. It has 
been demonstrated, however, that more than four effects can- 
not be used satisfactorily. Fig. 12 shows a modem multiple- 
effect vacuum apparatus with three effects. 

The single-effect vacuimi pan is used where there are com- 
paratively small quantities of liquor to be evaporated. But 
in the largest packing houses the multiple-effect vacuum pans 
are employed in concentrating glue liquors. 

84. With either kind of apparatus, open or vacuum, the 
clarified glue liquors are evaporated to a thick consistency 
so that they will set to a firm jelly within 10 or 12 hours. The 
concentrated glue liquors are run from the evaporating ap- 
paratus into molds, or boxes, for forming the desired cake of 
jelly. These molds are usually made of galvanized iron and 
hold about 50 pounds of the glue liquor. They are made flaring 
so that the glue jelly may be easily emptied from them. Any 
desired shape may be used, as there is no general standard. 

The boxes are filled to within J inch of the top and are 
allowed to set in a well-ventilated room protected from extremes 
of temperature until the jelly has become hard and firm. Some 
establishments set the boxes in a tiough of cold, running water 
and allow them to be cooled in this way. Under no circum- 
stances should the glue liquor be allowed to freeze or to remain 



60 PACKING-HOUSE INDUSTRIES, PART 2 

too long in a moderately warm temperature. In the former 
case, the glue jelly will become so brittle that it cannot be cut, 
and in the latter, the liquor will decompose and become worth- 
less. The jelly in the boxes, when firm and in condition to be 
handled, is ready for cutting into sheets. 

A patented process for cooling, setting, and cutting the glue 
by a continuous operation is in use in one large factory. The 
glue liquor is chilled on a brine-cooled cylinder, which, revolv- 
ing slowly, dips the lower part into the glue liquor and carries 
enough of this liquor on its surface to form within one revolu- 
tion a thin layer of firm jelly. This can be wound off the cylin- 
der as an endless ribbon, cut by the machine into suitable 
sizes, spread on frames, and sent to the drying room. 

85. Cutting Glues. — The glue jelly is usually cut into 
sheets by wire machines although other kinds of cutting ap- 
paratus are used. The wire machines consist of frames of 
steel with wires set in such a way as to produce a slice of glue 
jelly of the desired thickness. In the old-style machine, the 
jelly is cut by movable wires; in the new style, the wires are 
stationary, being set in steel frames. These frames are about 
2 feet from one another, in line, so that when the cake of 
jelly moves on an endless belt each wire in turn cuts a slice of 
jelly. For cutting low-grade glues a knife-cutting machine 
is used. The circular knives are set on a shaft and spaced 
sufficiently far apart to make the desired thickness of the sheet 
of jelly. With this machine the tops with the bubbles and 
the bottoms with the settlings are removed; later these are 
remelted with fresh material. 

86. The sheets of glue after cutting are spread on nets of 
galvanized-iron wire having meshes of about 1 inch. These 
nets have a framework of wood that sets into another frame 
built on a truck. As fast as the nets are covered with sheets 
of glue they are placed on the truck. This truck when filled 
is run into the drying room where the glue remains until dry. 
Although perfectly dry to the touch, the glue ordinarily con- 
tains from 10 to 13 per cent, of moisttire. Excessive drying of 
the glue is not desired by the manufacturers for obvious reasons. 



PACKING-HOUSE INDUSTRIES, PART 2 61 

In a heated chamber furnished with fans or blowers, the drying 
operation occupies at the present day only a few hours ; whereas, 
formerly, by exposure in airy lofts, it took several days. 

Sheets of glue that are imperfect or broken, if of cheap 
quality, may be made into ground glues by passing the material 
through a grinding mill. Where the glue is of high quality, 
imperfect sheets and pieces are remelted with the next batch 
of high-grade material. The lighter the glue— strength, clear- 
ness, etc., being equal — the better will be the price obtained 
for it. 

87. Yields of Glue.— From green-salted hide trim- 
mings, sinews, etc., from 18 to 20 per cent, of glue may be 
obtained. These materials when dry yield from 50 to 65 per 
cent., according to quality and condition. From hard, dry 
bones an average yield of 18 per cent, is obtained. From 
green rib bones — practically the only way this material is 
worked up for glue— an average yield of 12 per cent, of glue 
is obtained. 



PACKING-HOUSE INDUSTRIES 

(PART 3) 
Serial 414C Edition 3 

VARIOUS ANIMAL PRODUCTS AND 
THEIR DISPOSITION— (Continued) 



CURED MEATS 

1. The curing of the meat products of the packing house 
is such a wide subject that it cannot be treated in full here. 
The principle underlying the curing process in either the wet 
(pickle) or the dry (salt) way, is the prevention of putre- 
faction of the products by means of salt and other curative 
agents. Among the latter are saltpeter, wood smoke, vin- 
egar, etc. Salt alone may be used but to obtain the best 
results for mild cures its harsh effect is toned down with 
sugar, sirup, or molasses. When these saccharine substances 
are used in conjunction with brine or dry-salt curing, the 
meats are termed sweet-pickled meats. 

In connection with the curing and preserving of meats, 
the wholesomeness of any colors, preservatives, or other 
substances added to foods of any description in the packing 
houses, is determined by the Secretary of Agriculture, who 
promulgates the names of those substances which are per- 
mitted or inhibited in food products. The secretary also 
determines from time to time the principles that shall guide 
the use of colors, preservatives, etc., and the principles so 
established become a part of existing regulations. Where 
meats are to be exported, however, the use of preservatives is 

COPYRIGHTED BV INTERNATIONAL TEXTBOOK COMPANY. ALL RIGHTS RESERVED 

391'— 9 



2 PACKING-HOUSE INDUSTRIES, PART 3 

permitted under certain conditions (see Packing-House Indus- 
tries, Part 1). 

2. Dry-Salt Meats. — Meats that have been cured by 
covering with salt and piled about 6 feet high on the floor of 
the curing cellar are known as dry-salt meats. A small pro- 
portion of saltpeter is frequently mixed with the salt to give 
to the lean meat the ruddy appearance always desired. These 
cuts of meat are taken down and repiled three or four times 
during the period of curing. This operation is technically 
termed overhauling, the object being to allow the salt and 
brine made by the moisture in the meats to afifect all parts 
of the cut equally. The time allowed for curing these articles 
in packing houses is based on 1 day per pound of the weight 
of the cut. The dry-salt method of curing is most largely 
and almost exclusively applied to pork products. Dry-salt 
meats are shipped for domestic trade in bulk, and for export 
trade, packed with borax in boxes. 

3. Wet-Cured Meats. — Both pork and beef products are 
cured in brine or in pickle. The distinction between these 
terms is that the former is a solution of salt in water, while 
the latter is brine to which various permitted ingredients such 
as sugar and saltpeter have been added. The following cuts 
of meat are ordinarily cured by this process: pork hams and 
bacon before smoking; beef hams before drying; pork, beef, 
and sheep tongues before canning; and beef marketed as 
corned beef. 

Each establishment has its own formula for making pickle 
and its own method of curing in this solution. The time 
required for curing meats in pickle varies according to many 
circumstances, such as the strength of the pickle (percentage 
of salt) and the size and nature of the cut. While a piece of 
bacon weighing 4 or 5 pounds may be cured in 21 days, a 
very large ham may require over 100 days. During the 
process all the pieces of meat are subject to frequent over- 
hauling. 

Small pieces of beef to be used for canning purposes are 
cured in 15 days, as their small size — 4 to 6 pounds — permits 



PACKING-HOUSE INDUSTRIES, PART 3 3 

them to be readily permeated by the pickle. Even then, as 
with all pickled meats, they require frequent disturbance or 
transfer from one vat to another to insure a uniformly cured 
product. 

With the exception of hams, all meats are cured by simple 
immersion in the pickle or brine. The thickness of the ham, 
however, prevents the pickle from penetrating the meat before 
decomposition sets in. To overcome this difficulty, a long, 
hollow, nickel needle is pushed into the ham and the pickle 
forced through it by means of a pump and into the meat. The 
pickle is usually pumped into the ham at the stifle joint, the 
aitch bone, and in the shank. After being pumped the hams 
enter the curing vats where they receive the usual treatment 
as described. The pumping pickle is much stronger than the 
curing ^pickle, often consisting of a saturated salt solution 
containing varying amounts of sugar and nitrate. The curing 
pickle may contain 15 to 20 per cent, of salt with small 
amounts of sugar and nitrate. 

4. Box-Cured Meats. — The better grades of bacon are 
dry-cured by what is known as the box method. The meats are 
first rubbed on both sides with a mixture of salt, saltpeter, 
and sugar. They are then packed rind side down in air-tight 
boxes. Each layer is firmly tamped into the box and spread 
over with more of the curing mixture. During the cure, which 
requires about 20 days, the lid is held firmly on the box by 
means of heavy weights. This method of curing is followed 
by the regular smoking. 

5. Vinegar-Cured Meats. — Various small parts of the 
beef, sheep, and especially the hog, are cooked and pickled in 
vinegar and sold in this condition. Among the products 
handled in this way are beef tripe, pork and sheep tongues, 
pigs' feet, etc. 

6. Smoked Meats. — Meats prepared by dry salt and 
vinegar cures are sold in this condition, while those handled 
in the other two ways are subjected to further treatment. 
Corned beef, and pork and beef tongues are generally canned. 



4 PACKING-HOUSE INDUSTRIES, PART 3 

although beef tongues may be smoked. Beef hams are dried, 
forming the dried beef of commerce. 

Whether the final process be canning, drying, or smoking, 
the meat is soaked in water, after coming from the curing vats, 
to remove the excess pickle. Hams, bacon, and some other 
cuts are subjected to smoking as a further means of assisting 
in the preservation of the products. The object of putting the 
nieats into smoke is twofold — first, to evaporate a portion of 
the moisture of the meat and, second, to impregnate the prod- 
ucts with creosote and other empyreumatic compounds, the 
latter giving to smoked meats their characteristic flavor. 

7. The meats are hung in a smoke house; that is, an 
enclosed compartment at the bottom of which slow, smolder- 
ing fires are kept burning. Hardwoods and sawdust are used 
for fuel to produce the required smoke, as soft woods contain 
too much resinous matter which produces harmful effects on 
the meat. 

The products remain in contact with the smoke for a 
period depending on many conditions, which are judged by 
personal observation. Among these are the depth of color 
desired, size of pieces, temperature, etc. A shrinkage of 
weight always takes place in this process, which depends also 
on circumstances ; a general average of loss in weight may be 
taken as from 7 to 9 per cent. 

The smoked products are removed from the smoke house 
and allowed to cool at the natural temperature of the room, 
when they are ready to be sold or packed for shipment. 



BLOOD ALBUMIN 

8. Preparation. — Blood albumin is one of the products 
made from the blood of slaughtered animals. The blood as it 
comes from the animal is caught in shallow pans, each being 
just large enough to hold the blood of one animal, or it is 
caught in pails and immediately poured into shallow pans with 
as little agitation as possible. The blood is then allowed to 
rest without stirring or agitation until it clots. It is an 



PACKING-HOUSE INDUSTRIES, PART 3 5 

essential part of the process of manufacture that the blood 
should not be stirred, or it will be defibrinated and the proper 
separation cannot be made. 

After clotting, the clot is scored into small squares with a 
sharp knife, and these pieces are placed in shallow pans with 
perforated bottoms through which the serum or albumin drains 
from the clot. It is better practice to place these pieces on a 
draining table arranged so that the serum runs into a trough. 

The dark-red clot is used for the manufacture of ordinary- 
dried blood. When separated from further impurities and 
dried under suitable conditions, the serum that drains through 
is the product that forms the dried albumin of commerce. 
The serum at this stage of the process is of a pinkish or light- 
red color which is due to the presence of some red corpuscles 
that have been imperfectly separated by clotting. 

9. The next operation is to separate these red corpuscles, 
as the quality of the finished product depends on the perfec- 
tion of this separation. The serum is placed in shallow pans 
which are about 3 feet long by 18 inches wide and 4 or 5 inches 
deep. At the center of the bottom of these pans is a per- 
forated rubber stopper through which a ^-inch glass or lead 
tube extends until it reaches just above the surface of the 
liquid. The pans are filled with the serum and allowed to 
stand in a cool place for a few hours during which time the 
red corpuscles begin to sink. As the liquor clears at the top 
and the corpuscles sink lower and lower the tube is gradually 
lowered to draw off the clear serum into suitable vessels placed 
underneath, this operation being performed at intervals as long 
as the liquid runs off clear. When it is seen that further con- 
tinued settling will not produce a clear liquid, the receptacle 
beneath the pan is changed and the liquid that afterwards 
comes over is used in making inferior grades of the product. 

The serum that has drained off clear is of a very delicate 
pink color. It is placed in small, shallow, smooth enameled 
plates resembling ordinary pie plates, each of which holds 
about i pint. Previous to filling, the plates are slightly greased. 
The plates with the serum are then placed in a drying room 



6 PACKING-HOUSE INDUSTRIES, PART 3 

and kept at a temperature of about 110° F. until the product 
dries. The dried albumin is then scraped off the plates, which 
operation is easily accomplished, as the film of grease prevents 
it from adhering. It is important that the temperature of the 
drying room be kept as low as possible and yet dry the product 
in a few hours. Otherwise there is danger of the serum 
coagulating and rui-ning the product. 

The darker-colored albumin is dried in the same manner 
as the preceding. The first and best grade is a very clear 
and pale amber-colored product, its quality and value depend- 
ing very much on its lightness of color. Blood albumin finds 
extensive use in the textile industries in printing cotton fabrics, 
or as a glue insoluble in water. 

As liquid blood is a very perishable product, it is necessary 
that all the operations should be performed at a comparatively 
low temperature, about 38° to 40° F., to avoid decomposition 
and consequent inability to make albumin from the blood. It 
was customary formerly to manufacture the product only in 
winter, but with the modern system of artificial refrigeration 
it is possible to turn out a uniform product at all seasons. 

In the very latest methods of manufacture the separation 
of the serum is accomplished by centrifugal machines, and the 
evaporation is subsequently conducted at a low temperature in 
a vacuum apparatus. Most of the product on the market, how- 
ever, is still made by the old process, as the product produced 
by the centrifuge has not as good a color and the air-dried 
product is more soluble than the albumin made by the vacuum 
drier. 

The yield of blood albumin from blood is theoretically 50 per 
cent., but this is never realized in practice. Five bullocks 
yield about 4 J gallons of serum which when dried gives 
4J pounds of albumin. The blood of twenty sheep or thirty- 
four calves gives the same quantity of blood albumin. 



PACKING-HOUSE INDUSTRIES, PART 3 



DIGESTIVE FERMENTS 

10. All known digestive ferments belong to the class of 
soluble, or unorganized, ferments. They are sharply dis- 
tinguished from the insoluble, or organized, ferments such as 
yeast, in not having the powers of self-nutrition and self- 
multiplication. In composition, digestive ferments, resemble 
proteid substances, and contain carbon, hydrogen, oxygen, and 
nitrogen in somewhat similar proportions, to albumin. None 
of these ferments has yet been obtained in a state of absolute 
purity. All digestive ferments are soluble in water and are 
diffusible, though with difficulty, through animal membranes 
and parchment paper. They are precipitated from their 
watery solutions by absolute alcohol, but, unlike other proteids, 
with the exception of peptone, they are not truly coagulated by 
alcohol. When the alcohol is removed the ferments are still 
found to be soluble in water and to retain their activity 
unimpaired. All digestive ferments are coagulated and 
rendered permanently inert by the heat of boiling water; and 
when in solution, they are coagulated and destroyed by a 
temperature of about 160° F. 

The digestive ferments produced in the packing house are 
mainly pepsin and its products,, the former, however, being 
most commonly made. 

11. Pepsin. — The mucous membrane of the stomachs of 
hogs is the chief source of pepsin, although the stomachs 
of other animals may be used. The large and steady supply 
of material from hogs makes it most conveniently available. 
The stomachs are emptied of their contents and thoroughly 
washed in cold water. Any food that clings to the mucous 
membrane is removed by hand. In the washing, violent, ener- 
getic motions should be avoided or a great deal of the pepsin- 
containing membrane is liable to be removed mechanically. 
Gentle handling is essential during the first stages of the 
preparation. The outsides of the stomachs are trimmed away. 

That portion of the stomach reserved for the pepsin is 
chopped into small pieces and placed in water acidulated with 



8 PACKING-HOUSE INDUSTRIES, PART 3 

from 3 to 4 per cent, of pure hydrochloric acid. The receptacle 
used for this purpose in the packing house is usually a large 
open hogshead. The material is allowed to remain in this weak 
acid solution and is kept at a temperature of 104° to 122° F. 
until it undergoes self -digestion. This operation is materially 
assisted by frequent stirring, but from 36 to 48 hours at least 
is required for the solution to be effected. At this stage of 
preparation, the liquid is very prone to decomposition and 
great watchfulness is required. An innocuous, antiseptic con- 
dition is occasioned by passing sulphur dioxide into the solution 
from a generator until the solution smells strongly of the gas. 
This operation also serves to bleach the product. 

In this condition the liquid is allowed to stand and clarify 
itself by the precipitation of the mucus without causing any 
material injury to the pepsin from putrefactive changes. The 
resulting clear liquid is decanted or drawn off, and to it is then 
added common salt, the temperature of the liquid being main- 
tained at 94° F. until complete separation of the pepsin results 
by precipitation. The pepsin thus obtained — the floating scum 
— when collected, pressed, and dried constitutes crude pepsin, 
which even in this form is marketable, being very active and 
meeting certain requirements of trade. The product has a 
faint but not disagreeable odor, a brownish-yellow color, and 
a slightly saline taste. 

Another method is to evaporate the settled liquid in a vacuum 
pan at a temperature not above 105° F., and separate the salt 
and peptones by dialysis. This method does not require the 
use of sulphur dioxide. 

12. Purified Pepsin. — The crude pepsin, preferably 
but not necessarily in the moist state, is dissolved again in 
weak hydrochloric acid and the solution thus obtained is sub- 
jected to dialysis by any suitable means until the salt has been 
eliminated from the pepsin solution. The purified liquor is 
then concentrated, preferably in vacuum apparatus, care being 
exercised not to have the heat exceed 100° or 105° F. The 
concentrated solution is then dried on glass plates the edges of 
which are raised to hold it. These plates are about 15 inches 



PACKING-HOUSE INDUSTRIES, PART 3 9 

wide and 20 inches long, with the projecting edge J inch high. 
The thin layer on the plates is dried as rapidly as possible in 
a drying room that is arranged with shelves to hold a number 
of plates. The temperature should not exceed 102° F. in this 
room, which must be well protected from dust. When thor- 
oughly dry the pepsin (now the so-called pure pepsin of trade 
known as scale pepsin) is scraped from the glass plates. It 
will have a digestive power of about 1 to 3,000 — that is, 1 part 
of pepsin will digest 3,000 parts of freshly coagulated Qgg 
albumin — if the operation has been properly performed. By 
further redissolving and dialyzing, the digestive power may be 
greatly increased, but ordinarily the price obtained is not 
commensurate with the labor and expense involved. The pre- 
ceding strength — 1 to 3,000 — is the standard requirement for 
pharmaceutical and medical purposes. 

13. Powdered Pepsin. — The scale pepsin made by the 
foregoing process is ground in any suitable mill in which the 
material is protected from the atmosphere during the process 
of grinding. This is necessary as the scale of pepsin is so 
hygroscopic in its nature that attempts to powder it without 
this precaution will prove futile. Several suitable mills, readily 
available and very serviceable for this purpose, are on the 
market. Powdered pepsin is made into pills, tablets, etc., and 
has the same digestive power as the scale pepsin from which 
it is made. 

The compound preparations of pepsin enter into the field 
of the pharmacist rather than that of the chemist and will not 
be treated here. 

14. Yield of Pepsin. — The yield of pepsin varies with 
the class of hog stomachs used. From a test of 3,318 pounds 
of membranes, trimmed for pepsin making, a yield of 
117 pounds of high-grade pepsin was obtained. The weight of 
membranes from 250 whole hog stomachs was 200 pounds, 
thus giving a yield of 2.8 pounds of pepsin for each 100 
stomachs. Another test from 9,000 stomachs gave a yield of 
162 pounds, or 1.8 pounds of pepsin for each 100 stomachs. 



10 PACKING-HOUSE INDUSTRIES, PART 3 

The labor attached to the manufacture of pepsin is very 
sHght. Ordinarily, one pepsin maker, with a boy, accomplishes 
the entire manufacture at a comparatively small cost. 

Pepsin in a dry form, in common with all digestive ferments, 
permanently retains its properties. Moisture and heat are 
favorable to its decomposition and it is essential that it should 
be so prepared as to have peptone and all other substances of 
hygroscopic properties eliminated as completely as possible. 
Digestive ferments remain inert, and are not injured in the 
least by a low temperature. Pepsin exerts its activity in acid 
solutions only, while pancreatin acts best in neutral or alka- 
line solutions. 

15. Valuation of Pepsin. — The chemist is frequently 
called upon to determine whether pepsin meets the require- 
ments of the standard strength. The most approved method 
for the testing of pepsin is that officially given in the ninth 
decennial revision of the pharmacopoeia of the United States 
of America. The method is as follows: 

Mix 25 mils* of normal hydrochloric acid with 275 mils of 
distilled water and dissolve .1 gram of pepsin in 150 mils of 
this liquid. Immerse a hen's egg, which is not less than 5 nor 
more than 12 days old and has been kept in a cool place, in 
boiling water for 15 minutes. As soon as the egg has been 
sufficiently cooled to handle it, remove the pellicle and all of 
the yolk ; at once rub the albumen through a clean, dry, hair or 
brass No. 40 sieve, reject the first portion that passes through 
the sieve, and place 10 grams of the succeeding portion in a 
wide-mouthed bottle of 100 mils capacity. Immediately add 
2 mils of the acid liquid and, with the aid of a rubber-tipped 
glass rod, moisten the albumen uniformly. Again add 2 mils of 
the acid liquid, repeat the manipulation with the glass rod, and 
with gradually increasing portions of the acid liquid, until the 
total amount added measures 20 mils. Thoroughly separate 
the particles of albumen from each other, rinse the rod with 
15 mils more of the acid liquid, and, after warming the mix- 
ture to 52° C, add exactly 5 mils of the solution of pepsin. 



*One mil is the equivalent of 1 cubic centimeter. 



PACKING-HOUSE INDUSTRIES, PART 3 11 

At once cork the bottle securely, invert it three times, and 
place in a water bath that has previously been regulated to 
maintain a temperature of 52° C. Keep it at this temperature 
for 2^ hours, agitating the contents every 10 minutes by invert- 
mg the bottle once. Then remove it from the water bath, 
pour the contents into a conical measure having a diameter not 
exceeding 1 centimeter at the bottom, and transfer the undi- 
gested tgg albumen which adheres to the sides of the bottle, 
to the measure, with the aid of small portions of distilled 
water, until the total amount used measures 50 mils. Stir the 
mixture well and let it stand for J hour; the deposit of undis- 
solved albumen does not then measure more than 1 mil. 
The relative proteolytic power of pepsin, stronger or weaker 
than that just described, may be determined by ascertaining 
by repeated trials the quantity of the pepsin solution, made as 
directed in the assay, required to digest, under the prescribed 
conditions, 10 grams of boiled and disintegrated tgg albumen. 
To ascertain how many parts of tgg albumen 1 part of pepsin 
will digest, divide 15,000 by this quantity expressed in mils. 

16. Apparatus for Making Pepsin. — The necessary 
apparatus for manufacturing pepsin and compound prepara- 
tions of it includes the following: 

Mill, sifter, or bolter, percolators, funnels, glass plates for 
drying, glazed stone jars, the necessary hogsheads, barrels, etc. 

For making the pepsin tablets, pepsin 'glycerol, essence, wine, 
and aromatic pepsin, a hot-water bath, hot-water funnel, and 
several glass bottles and funnels are necessary, in addition to 
the tablet machine. 

17. Peptone. — By allowing the solution from which the 
pepsin precipitate has been removed to cool gradually, the salt 
will crystallize out. This solution contains practically all the 
peptones, and after the salt has crystallized from it the peptones 
are left in solution from which they ipay be obtained by 
evaporation and drying. There is a limited market for this 
product, however, and it is not manufactured extensively. The 
physiological characteristics are made use of to a much greater 
extent in other compounds, such as beef peptone. 



12 PACKING-HOUSE INDUSTRIES, PART 3 

18. Beef Peptone. — The compound known as beef pep- 
tone is made by digesting beef with the pancreas of the 
beef. The tougher and leaner the beef, the better will be the 
yield of beef peptone. The meat is very finely minced and to 
25 parts are added 8 parts of the pancreas and 4 parts of 
water. The whole is allowed to digest in a jacketed kettle at 
a temperature not exceeding 130° F., for 6 hours, after which 
all the solids will, through a true digestive process, have passed 
into solution. During this time the mixture must be frequently 
stirred to facilitate the action. The solution is filtered through 
cotton-flannel bags in the same manner as beef extract and the 
filtrate is bleached the same as pepsin solution for which pur- 
pose the same apparatus will serve. 

The bleached solution is evaporated to dryness on a water 
bath or at a temperature not exceeding 212° F. It may also 
be economically evaporated to a thick consistency in a vacuum 
apparatus and afterwards dried. The yield of beef peptone 
from this process, using tough and lean meat, is 13 to 14 per 
cent, of the total weight of the meat and pancreas. This yield 
is rather high for the ordinary run of beef, from which a yield 
of about 10 per cent, should be obtained. 

19. Pancreatin. — The product known as pancreatin is a 
digestive ferment existing in the fluids of the pancreas, or 
sweetbreads, of animals. Pancreatin is ordinarily made from 
the pancreas of the hog, in a similar or analogous manner to 
that of pepsin from hog stomachs. This product is not made 
to any extent in the average packing house as it borders on the 
field of the pharmacist. 

The pancreatin solution, like the pepsin, is also very sus- 
ceptible to decomposition, which may be and usually is pre- 
vented by the addition to the solution of an infinitesimal amount 
of thymol or chloroform, either of which does not interfere 
with the action of the ferment. Ordinarily a dry defatted 
pancreas product is manufactured and is as satisfactory as the 
extract. 

20. Rennet. — The fourth, or true, digestive stomach of 
the calf is utilized in preparing rennet. This product is not 



PACKING-HOUSE INDUSTRIES, PART 3 13 

prepared in the packing house, the stomach being simply fresh 
frozen and sold in that condition. 

A crude rennet may be prepared by simply trimming the 
calf stomach free from fat, etc., drying it at a low temperature, 
and then grinding it to a fine condition. The ground material 
is packed tightly in a glass or tin percolator, and any remain- 
ing fat (which would become rancid through oxidation) is 
extracted by means of low boiling petroleum, ether, etc. The 
fat-free, crude rennet is afterwards spread thinly and then 
heated gently to drive off the odor of the solvent. 

Commercial rennet is prepared in almost the same manner 
as pepsin. The washed and cleaned tissue is cut into small 
pieces and allowed to self-digest in a 2 to 3 per cent, cold 
hydrochloric-acid solution for 2 days. The undigested matter 
is strained off and the liquid saturated with common salt. The 
rennet which separates is collected and dried, and constitutes 
the crude rennet of commerce. This must comply with the 
definition and tests of the National Formulary, which are as 
follows : 

Rennet is a partially purified milk-curdling enzyme obtained 
from the glandular stomach of the calf, and is capable of 
coagulating not less than 25,000 times its weight of fresh milk. 
Rennet of a higher coagulating power may be brought to the 
standard by admixture with sodium chloride and sugar of 
milk. 

Assay. — Mix .10 gram of rennet with 50 mils of distilled 
water by stirring (vigorous shaking or violent agitation of this 
liquid must be avoided). Allow the liquid to stand for exactly 
15 minutes. Place 50 mils of cow's milk in a beaker about 
12 centimeters in height and 5 centimeters in width. Warm 
rapidly on a water bath to 43° C, add 1 mil of the rennet 
solution and stir the mixture slowly for 10 seconds. Maintain 
the temperature of the bath of the rennet solution at 43° C. 
for 10 minutes, remove the beaker from the bath and tip it 
at an angle of 45°. The milk will by this time have lost its 
fluidity to the extent of exhibiting a decidedly convex surface. 
An additional 30 seconds on the water bath produces a firm 
curd. 



14 PACKING-HOUSE INDUSTRIES, PART 3 



ANIMAL EXTRACTS 

21. Method of Manufacture. — Animal extracts are 
made from various organs and tissues of slaughtered animals. 
Modern medicine has recognized many of these as having 
great curative value. Some of the larger packing companies 
have established special laboratories for their manufacture 
while others sell raw products to pharmaceutical houses making 
a specialty of these products. The present-day methods of 
preparation are very largely trade secrets. 

Of these animal extracts the most important are : pituitary 
extracts made from the pituitary bodies located at the base 
of the brain ; the suprenal extracts made from suprenal glands 
located above the kidney; thyroid extracts from the thyroid 
gland located in the throat. While these three extracts are 
perhaps the most important, there are a great many others 
of value made from other organs or tissues. Among these 
are the spinal cord and brain substance, ovarian substance 
from the ovaries of cattle and hogs, and many others. 
Although details of making most of these substances are secret, 
the animal extracts are usually made by very carefully drying 
the substance, removing the fat, and then preparing the 
substance in powder form. 

The control and standardization of these preparations is 
a very difficult and delicate matter and requires the work of a 
highly trained physiological chemist and one who is familiar 
with the latest literature and methods. The tendency at the 
present time is toward manufacturing the extracts at the large 
packing centers because of the fact that it is very desirable to 
handle these substances while fresh. It is very probable that 
in the future this will become an important branch of the pack- 
ing industry. 



PACKING-HOUSE INDUSTRIES, PART 3 15 

TANKAGES AND FERTILIZERS 

22. Tankag-e. — In the packing house there is always 
more or less material which is unfit for human consumption. 
At one time this waste material of the packing house was not 
only a nuisance, but the disposal of it was a source of expense. 
Now, however, all refuse is utilized by making it into the 
various grades of tankage, which are a source of income of 
no inconsiderable importance. These tankages are either used 
as stock foods or enter into the manufacture of fertilizers. 
These stock foods are sold on a guarantee to contain not less 
than 60 per cent, of protein. The content of fat, carbohydrate, 
and crude fiber is also guaranteed. The use of tankage as a 
fertilizer material will be described later. 

The name properly applied to the sediment remaining in the 
tanks where meat scrap, with some bone, is rendered to separate 
the fat is tankage. The name is also applied to the refuse 
from tanking garbage, the dried product being known as 
garbage tankage. This product, however, is never made in 
packing houses. The name tankage is also loosely applied to 
mixtures that consist largely of bone and do not differ greatly 
in composition from pure bone. 

After material has been cooked in the rendering tanks the 
fat is withdrawn from it, and when all that can be taken from 
the tank has been obtained, the cooked, hot, material is allowed 
to drop into a box or vat located in front and underneath the 
tank. Here the material is kept hot by steam pipes in the vat, 
and whatever grease or fat rises to the surface is skimmed ofif. 
The latter is technically known as skimmings, and is recooked 
with the next charge of fresh material. 

The water with which the material in the tank has been 
cooked becomes impregnated with more or less fat and also 
with a very large quantity of nitrogenous material. It is 
technically known as tank water and is the source of con- 
centrated tankage, or stick. The treatment of tank water will 
be described later under the heading Concentrated Tankage. 

The material in the vat after skimming is drained free 
from the tank water, and while still hot is placed in the tank- 



16 



PACKING-HOUSE INDUSTRIES, PART 3 



age or fertilizer press. This operation is ordinarily performed 
by hand, but in the modern establishments the tankage is made 
to flow from above into the press cloth on the forms that are 
placed on the platform of the press. 

23. Pressing- Tankage. — There are several forms of 
fertilizer presses in use. Among these are the knuckle-joint, 
the power-screw, and the hydraulic press. Fig. 1 shows the 




Fig. 1 

power-screw press, which is the style of fertilizer press pre- 
ferred by many of the leading packers, and only by the use 
of this or similar presses have they been able to handle the 
immense amount of material that is now utilized and made 
into valuable fertilizer. This press has the advantage of 
giving the same pressure at every point, thus pressing a small 
amount of material as well as a large amount without the 
handling of any blocking. It is made very heavy and strong 



PACKING-HOUSE INDUSTRIES, PART 3 



17 



to stand rough usage and will give an immense pressure. 
Although shown with a double platform, it may be fitted with 
any other style of platform to suit the situation. 

24. The cloth used for pressing tankage is made espe- 
cially for this purpose. It is known as tankage press cloth, 
and is made of rather coarsely, but strongly, woven jute. A 
rack, Fig. 2 (a), is first placed on the platform a of the press. 
This rack is square and is made of wooden strips f inch thick 
by ^ or If inches wide. These strips are placed i inch apart, 
with five or more elm strips 2 inches wide and f inch thick 
nailed across. Wrought-iron nails of sufficient length to clinch 
securely in the elm 

are used. 

25. The platforms 
a and b, which run on 
a track, may be filled 
at any convenient 
place and afterwards 
run to the press. On 
the rack is placed a 
form like that shown 
in Fig, 2 (b). This 
form is square inside 
and 3J inches deep. 
It is made by nailing 
together boards 1 
inch thick by 3^ 
inches wide, in the 
form of the sides of a box. A board is then nailed across 
each end, as shown, to serve as a guide and to give stiff- 
ness. Over this form is spread a cloth which is filled 
with tankage until the material is even with the top of the 
form. The cloths should be sufficiently large to enable the 
sides and ends to be folded over, thus completely covering 
the material. The form is then raised and another rack is 
placed on the layer thus made, the form being placed on this 
new rack, a cloth again placed over it, and another layer of 

393—10 




18 



PACKING-HOUSE INDUSTRIES, PART 3 



wet tankage put in as before. From eight to twelve racks 
are used in one load and as many cloths less one. When 
the last layer is made, the form is taken off and a rack is 
placed on top of the load. The platform is then run on the 
track e to the press, and the pressing begins. By placing the 
racks alternately across and lengthwise of the platform, the 




Fig. 3 



built-up load will be less liable to move or to cant over and 
thus cause the racks to spread. A guide should be used in 
building the layers, so that the form will always be directly 
over the last layer. The load consisting of the different layers 
of material to be pressed is sometimes termed a cheese. 

26. The power in pressing is applied by the pulleys d, 
which cause the gears to move the upper part c oi the press 



PACKING-HOUSE INDUSTRIES, PART 3 19 

downwards, thereby pressing out the water and grease remain- 
ing in the wet tankage. The racks afford channels for this 
water and grease to run out of each layer. By a reverse 
motion of the power the upper part of the press is raised when 
the pressing is finished. 

The advantage of the double platform is that while one 
load is being pressed on one side a, another may be built on 
the other side b. 

27. In Fig. 3 is shown the knuckle-joint fertilizer press 
with one load pressing and another load of material in layers 
ready for running under the press when the first pressing is 
finished. The press is shown with double platform and power 
attachment, although if desired presses with single platform 
and hand-power attachment can be procured. For small pack- 
ing houses this press has been found very satisfactory. 

28. In using hydraulic presses for tankage, it is necessary 
to block the load by placing square pieces of wood between 
the load of layers and the upright guides on the press. The 
hydraulic press does excellent and rapid work and presses the 
material very much drier than either of the presses illustrated. 

The pressed material contains approximately 50 per cent, of 
moisture after being removed from the press and shaken free 
from the cloths. The water and grease pressed out of the hot 
tankage run to a catch basin, where the grease rising to the 
top is skimmed off and recooked with refuse material for 
No. 2 tallow, or for yellow grease. 

29. Drying tlie Pressed Tankage. — The pressed mate- 
rial is now transferred to the drier for the final drying into a 
commercial product. Several forms of driers may be had. 
Fig. 4 shows one of the most modern makes known as a single- 
cylinder drier. It is extremely simple in operation. The iron 
cylinder ^ is a jacketed, or double, shell in which are revolving 
arms, or paddles, operated by the shaft b. The fertilizer mate- 
rial to be dried is loaded into the cylinder through the door c, 
which is then closed, and the shaft is started revolving by the 
large cog wheel / operated by the power applied to the pulley e. 
Steam under pressure circulates through the double shell and 



20 



PACKING-HOUSE INDUSTRIES, PART 3 




-^3^537 



the heat from it drives 
off the moisture in the 
material. The odors 
and gases coming 
from the fertilizer 
material pass through 
the pipes to the con- 
denser which is at- 
tached to all driers. 
The condenser has 
jets of water running 
into it which, coming 
in contact with the 
hot gases, cool them 
and at the same time 
cause the greater part 
of them to pass into 
solution with the 
water. The cylinders 
of the drier vary from 
3 to 5 feet in dia- 
meter and are from 
10 to 16 feet long. 
The clutch g serves to 
start and stop the 
power that operates 
the drier. 

The tankage is dried 
so that it contains 10 
per cent, or less of 
moisture. This oper- 
ation requires from 3 
to 6 hours depend- 
ing on the class and 
quantity of material 
worked on. It is then 
allowed to drop out 
through the doors d. 



PACKING-HOUSE INDUSTRIES, PART 3 21 

The material is so hot that if it were piled up in this condition 
it would not become cold and would rapidly decompose. The 
hot material, therefore, is spread on the floor about 3 inches 
deep. After the heat has gone from it the material is shoveled 
into piles ; or if desired for immediate shipment, it is put into 
second-hand bags, such as salt bags, that will hold about 
200 pounds each of the dried tankage. 

Where the Wannenwetsch system (see Packing-House 
Industries, Part 1) of rendering is employed it is not neces- 
sary to use any press or drier for producing the finished 
tankage. 

30. Small renderers frequently use a drier in the form of 
a steam- jacketed drum that is about 6 or 8 feet in diameter and 
about 2J feet in height. This drum is provided on the inside 
with revolving or circulating arms for the purpose of prevent- 
ing the material from sticking to the sides and also to facilitate 
the removal of the moisture. After the tankage is dried the 
door in the side is opened, permitting the revolving arms to 
empty the drier automatically. These driers are built to with- 
stand a steam pressure of 75 pounds per square inch. 

31. Grading- of Tankage. — Tankage is divided into 
several grades, which are quoted by the percentages of 
ammonia and phosphoric acid shown by analysis. For 
example, a 7-30 tankage would be one that analyzes 7 per cent, 
of ammonia and 30 per cent, of phosphoric acid. Low-grade 
tankage contains less than 10 per cent, of ammonia and a high 
percentage of bone phosphate, while high-grade tankage always 
contains 10 per cent, or more of ammonia, and correspondingly 
less bone phosphate. Bone tankage, as the name implies, is 
that containing mostly bone. 

Tankage is also classed as unground, crushed, and ground 
tankage. The former is tankage that is dried without sub- 
sequent grinding or crushing of large sinews, meaty pieces, or 
bones. Crushed tankage consists of unground tankage broken 
up sufficiently to pass through a screen of about 1- or l^-inch 
mesh. Ground tankage is tankage ground to a fine condition. 
This material will pass through a sieve of about |-inch mesh 



22 PACKING-HOUSE INDUSTRIES, PART 3 

and constitutes the most valuable unfinished tankage. Tank- 
ages which are sold as animal foods are ground much finer so 
that they will pass through a 10-mesh sieve. These are the 
most valuable of all tankages. 

Tankage is always valued on the percentage of both ammonia 
(nitrogen) and phosphoric acid contained in it, the former 
being always the most valuable component. 

32. Concentrated Tankage. — In order to make con- 
centrated tankage, also known under the trade name stick, 
the tank water from the cooking of meaty material is evapo- 
rated. Tank water contains a considerable amount of dis- 
solved nitrogenous matter, which, when recovered in the form 
of concentrated tankage, furnishes a valuable fertilizer 
material. 

The tank water is run to receivers and thence to evapora- 
tors where it is evaporated to a sirupy consistency. The mix- 
ture is concentrated to about 30 per cent, of moisture, when 
it is placed about 1 inch deep in sheet-iron pans that are 
30 inches long, 15 inches wide, and 3 inches high. These 
are placed in a drying oven and the mixture is baked to 
dryness. The material is then knocked from the pans and 
ground fine. The product resembles ground blood and will 
analyze about 15 to 16 per cent, of ammonia on a dry basis. 
This material, like dry blood, is sold by the unit value, being 
quoted commercially at a certain price per unit. The unit is 
simply an arbitrary commercial standard, the chemical per- 
centage of ammonia being taken. One per cent, of ammonia 
equals 1 unit per ton. When large quantities of concentrated 
tankage are treated, the form of evaporator used is the 
vacuum pan, which evaporates such quantities in an economical 
manner. Where small quantities are to be evaporated, the 
roller evaporator, similar to Fig. 7, Packing-House Industries, 
Part 2, may be used effectively. 

33. Ground Blood. — In order to produce ground blood, 
the liquid blood is conducted from the slaughtered animals into 
a tank, or vat, where it is boiled with open steam for 20 minutes. 
This coagulates the albuminous matters and renders them prac- 



PACKING-HOUSE INDUSTRIES, PART 3 



23 



tically insoluble. The clotted blood is then pressed precisely 
the same as tankage. The pressed-out water is of no value 
and is allowed to go to waste. The cloth for pressing blood 
is of closer texture but of the same material as tankage cloth. 

The pressed blood from the fertilizer press contains about 
50 per cent, of moisture. It is broken into small pieces and 
passed through a disintegrator which tears it into shreds about 
the size of a bean. The blood in this condition is then passed 
to the drier from which it emerges as dried blood contain- 
ing, however, numerous hard lumps technically known 
as blood screenings. The blood is screened through a sieve 
and the screenings are ground by themselves to the required 
degree of fineness, and 
mixed with screened 
blood. Instead of sift- 
ing the dried blood as 
it comes from the drier, 
as is done in the large 
establishments, it may 
all be put through the 
mill and ground fine. 
The hot material is 
spread on the floor in 
a thin layer to allow the heat to escape, after which it is made 
into a pile or sacked like tankage. 

Ground blood is always sold on the unit basis of the 
ammonia it contains, the percentage of which will vary accord- 
ing to its freedom from extraneous material and moisture. 
Clean ground blood should contain from 16 to 17 per cent, of 
ammonia and from 8 to 19 per cent, of moisture. When mixed 
with refuse, it may not contain over 9 per cent, of ammonia. 

Where the amount of blood in comparison with the tankage 
is small, it is usually cooked along with the tankage. The 
resulting fertilizer is sold on the basis of its ingredients. 




Fig. 5 



34. Raw^ Bone and Ravr-Bone Meal. — The bones that 
have not been subjected to pressure in cooking, such as shin, 
knuckle, jaw, and head bones, furnish raw bone. After these 



24 PACKING-HOUSE INDUSTRIES, PART 3 

have been freed from grease as much as possible and dried, 
they are ground finely in a bone mill, making raw-bone meal. 
This mill is sometimes termed a disintegrator. In Fig. 5 the 
disintegrator is shown closed and in Fig. 6 it is shown open. 
A peculiarity of the bone mill is that the material is ground by 
impact on rounded iron bars and on itself. The open machine 
shows the revolving barred wheels. The inside wheel a 
revolves in the opposite direction from the outside one h, and 
both revolve at a very high rate of speed. As the bones are 
fed into the hopper the revolving wheels keep them flying 
around until they are in a fine, dusty condition, when they pass 
through the bottom of the mill. The material is screened and 

any pieces of bone that 
have escaped grinding 
are returned to the mill. 
If the grinding is care- 
fully done, this, how- 
ever, is seldom neces- 
sary. 

After cooking, raw 
bone contains so much 
of the original sub- 
stance that it is neces- 
sary, previous to grind- 
ing, to crush the bone 
by means of a bone crusher which is built on a plan similar to 
the ordinary rock or ore crusher. Raw-bone meal as produced 
In the packing house usually contains from 4 to 5^ per cent, 
of ammonia and from 20 to 25 per cent, of phosphoric acid. 




Fig. 6 



35. Steamed Bone and Ground Steamed Bone. 

Bones that have been cooked under pressure are used for 
making steamed bone and ground steamed bone. All bones 
that are neither useful nor desirable for other purposes are 
made into steamed bone. They comprise rib bones, large 
knuckles, back bones, etc. From these bones are produced 
tallow and glue liquors. For producing the latter, In connec- 
tion with steamed bone, special cooking of the bones is neces- 



PACKING-HOUSE INDUSTRIES, PART 3 25 

sary. When the bones are simply cooked for the tallow and 
residual bone, however, no special cooking is required. 

36. Cooking" Bones for the Recovery of Tallow 
and Steamed Bone. — In order to recover tallow and 
steamed bone the bones are put into the rendering tank and 
cooked from 7 to 10 hours at a steam pressure of about 
40 pounds per square inch, which effectually removes the 
tallow from the bones. After a period of rest to allow the 
tallow to rise, it is drawn of¥ and the bones and water are 
dumped into a vat from which any floating tallow remaining 
is removed. The water is evaporated to concentrated tankage 
if it contains sufficient nitrogenous matter to make it profitable. 
The cooked bones are very friable and porous. After drain- 
ing on the floor for several hours the bones are removed and 
placed in piles. The heat generated in these piles is amply 
sufficient to dry the bones without passing them through a 
drier. 

37. Cooking" Bones for the Recovery of Tallow, 
Glue Liquors, and Steamed Bone. — The method of cook- 
ing bones for the production of glue liquors, together with the 
tallow, is carried out as follows : 

The bones, which are loaded into a tank, are allowed to 
stand in water at a temperature of about 130° F. for 1 hour. 
This water is run ofif and, where beef extract is made, is used 
for this purpose. The bones are again covered with water 
and cooked for 6 hours with the tank uncovered. This is 
known as open cooking. The material is allowed to settle, 
and the resultant tallow is drawn off. The cover is now put 
on the tank and the bones are cooked for 2 hours under a 
pressure of 30 pounds per square inch. The glue liquor after 
settling is drawn off, more water is put on the bones and a 
further pressure cooking of 3 hours is given, after which the 
tallow and glue liquor are drawn off. The material is now 
cooked at a pressure of 40 pounds per square inch for a few 
hours when, after drawing off the tallow, the cooked bones are 
dumped from the tank into the vat underneath and treated as 
described. 



26 



PACKING-HOUSE INDUSTRIES, PART 3 



38. In Table I the results of tests on the boiling of rib 
bones are given. In test No. 1 the bones were boiled for the 

TABLE I 
RESULTS OF TESTS ON BOELING RIB BONES 



Test 


Dry Glue 
Per Cent. 


Tallow 
Per Cent. 


Dry, Steamed 

Bone 

Per Cent. 


No. I 

No. 2 


11.50 
21.27 


7.48 
10.88 


40.80 
31-64 



recovery of bone and tallow, and in test No. 2 the same mate- 
rial was boiled for the recovery of bone, tallow, and glue. 

In Table II are given the partial compositions of analyses 
of the dry, steamed bone obtained in the preceding tests. 

While the cooking for glue by this method consumes more 
time and is more laborious, the increased yield in the tallow 
obtained together with the value of the glue liquor makes it 
a more profitable method than cooking the bones for tallow and 
bones only. 

The average steamed bone will analyze from 2 to 3 per 
cent, of ammonia and about 60 per cent, of bone phosphate. 
The dried, steamed bone is made into steamed-bone meal by 
grinding in the ordinary bone mill. For this purpose the 

TABLE II 

PARTIAL COMPOSITIONS OF DRY, STEAMED BONE 



Test 


Ammonia 
Per Cent. 


Bone Phosphate 
Per Cent. 


Fat 
Per Cent. 


No. I 

No. 2 


3.66 


59-21 
72.01 


7.67 
2.33 



bones need not be previously crushed, as their brittle nature 
permits them to be very easily broken up. 



PACKING-HOUSE INDUSTRIES, PART 3 27 

30. Azotine. — The material known as azotine is made 
from the residue of cooked crackhngs which, after being sub- 
jected to high pressure to extract all the grease possible, is 
passed through a drier and then finely ground. The material 
will shrink in weight from 35 to 40 per cent, in passing from 
the raw to the finished state and loses at the same time several 
per cent, of ammonia. This material is not made in the large 
packing houses, but is derived mostly from small tallow and 
grease renderers. Azotine is sold on the unit basis of the 
ammonia it contains, that made from pork material containing 
about 2 per cent, more ammonia than that made from beef. 
Commercial azotine will analyze about 15 per cent, of ammonia 
on a basis of 10 per cent, moisture. 

40. Hoof Meal. — Cattle hoofs are used for making hoof 
meal. The hoofs are cooked in the pressure tank for 5 hours 
at a pressure of about 40 pounds of steam per square inch, 
after which they are dried thoroughly. Care must be taken 
to have the cooked hoofs perfectly dry, for if they contain 
any appreciable moisture it wall be impossible to grind them. 
The dried hoofs are ground in the regulation bone-grinding 
mill to the fineness of bone meal. With the hoofs may also 
be placed useless horns which also furnish hoof meal when 
ground. This material contains a large amount of nitrogen, 
analyzing on a dry basis over 19 per cent, of ammonia. An 
analysis of hoof meal gave 2.1 per cent, moisture and 19.05 
per cent, of ammonia. 



MIXED FERTILIZERS 

41. For mixing fertilizers to make complete fertilizers, 
it is necessary to add to the bones and tankage other materials 
as diluents, and also some form of potash. The latter is most 
commonly commercial potassium chloride and at times potas- 
sium sulphate. The sulphate is regarded as preferable, 
especially for tobacco fertilizers. The diluents, or fillers, may 
be any cheap material, such as ashes ground fine or earth, or 
any more or less bulky material. 



28 PACKING-HOUSE INDUSTRIES, PART 3 

Complete fertilizers are materials that contain the elements 
necessary for the growth of organic matter, which are first 
extracted from the soil by growing crops. They comprise 
nitrogen (ammonia), phosphoric acid, and potash. 

Direct fertilizers contain certain forms of plant food that 
contribute directly to the growth and substance of plants. 
Such materials may contain nitrogen, potash, or phosphoric- 
acid compounds, or any two, or all three, of these forms of 
plant food. 

Indirect fertilizers are those which do not in themselves 
furnish directly to the soil any needed plant food, but whose 
chief value depends on the power they possess of changing 
unavailable forms of plant food into available forms. Indirect 
fertilizers include lime, gypsum, and salt. 

42. Ingredients of Mixed Fertilizers. — Among the 
various and most common ingredients used in making com- 
plete fertilizers are dried blood, tankage, cottonseed meal, 
azotine, bones, potassium chloride, potassium sulphate, sodium 
nitrate, ammonium sulphate, and various forms of phosphates 
derived principally from phosphate rock. 

Tankage, containing, as it ordinarily does, from 7 to 10 per 
cent, of ammonia, is in too concentrated a form to be used by 
itself as a fertilizer and at the same time is too expensive. 
Although, as a rule, there is no objection to using tankage in 
its natural state, it lacks potash, which is a very essential 
ingredient in a commercial fertilizer. 

Bone, in the form of raw-bone meal, is used for a direct 
fertilizer. But the objection to using this material is the 
insoluble form of most of its phosphoric acid content. 

A source of nitrogen frequently used in complete fertilizers 
is found in sodium nitrate, or Chile saltpeter, which contains 
about 15i to 16 per cent, of nitrogen. This is ordinarily 
used in connection with the phosphates, tankage, and other 
nitrogenous materials. The disadvantage of using sodium 
nitrate is its free solubility in water, on account of which it 
washes out of the soil too readily. It is adaptable, however, 
for crops that mature quickly. 



PACKING-HOUSE INDUSTRIES, PART 3 29 

Of late years, owing to the constantly growing demand for 
nitrogenous material, cottonseed meal has been very exten- 
sively employed in making fertilizers. This material is 
comparatively cheap and is always available in steady quanti- 
ties. It furnishes an excellent raw material containing about 
7 or 8 per cent, of ammonia. 

Phosphate rock is a mineral phosphate found in various 
states. In a raw condition it contains from 25 to 35 per cent, 
of phosphoric acid. This acid, however, is in an insoluble 
condition and consequently must be treated with sulphuric 
acid before the phosphates can be made available. The quan- 
tity of acid required varies with the amount of phosphates 
present as determined by analysis. (See Quantitative Analysis.) 

Acid phosphates are known under various names such as 
superphosphates, dissolved rock, etc. They are formed by 
treating bones, bone black, bone ash, etc. with sulphuric acid, 
the result being soluble phosphates of calcium and calcium 
sulphate (gypsum) in nearly equal proportions. Bone prod- 
ucts are all valuable fertilizers, as they furnish phosphoric 
acid and ammonia. 

Discarded bone black from sugar refineries also furnishes a 
source of fertilizer material. This bone black, however, con- 
tains no nitrogen. 

Garbage tankage also contributes very largely to fertilizer 
material, this being its only use. 

Ammonium sulphate is a by-product from the manufacture 
of illuminating gas or coke. There are occasions, however, 
when its high price prevents it from being used in commercial 
fertilizers. 

Potassium salts, such as kainite, kaiserite, etc., used in the 
manufacture of fertihzers, are obtained principally from the 
Stassfurt mines. The potassium chloride, known commercially 
as muriate of potash, generally contains from 50 to 53 per cent, 
of actual potash. Potassium sulphate from this source ordi- 
narily contains from 48 to 51 per cent, of actual potash. 

Fish scrap is also used extensively in fertilizers. 

Basic slag, which is the phosphatic slag formed in the basic 
process of steel making, has been found in recent years to have 



30 PACKING-HOUSE INDUSTRIES, PART 3 

considerable value as a fertilizer. The phosphoric-acid con- 
tent varies from 10 to 25 per cent, and probably exists as 
calcium phosphate. The slag must be very finely ground in 
order to be of value as a fertilizer. 

4S. Mixing the Ingredients. — The raw materials just 
described are mixed in various proportions depending on 
the use of the fertilizer for certain crops and also on the sale 
price of the finished product. All materials should be in a 
finely ground condition as, in addition to its chemical com- 
position, the mechanical condition of a fertilizer is an impor- 
tant consideration, the degree of pulverization or fineness con- 
trolling to a great extent the rate of solubility of the 
ingredients. 

The mixing of the various ingredients is merely a mechan- 
ical operation and is most commonly done with some form of 
fertilizer mixer. It is essential that the several ingredients 
be thoroughly incorporated with one another. The most com- 
mon form of mixer consists of a shallow, revolving pan in 
which is placed apparatus for mixing the fertilizer while the 
pan is revolving. Any form of mixer that will fill the require- 
ments of thorough incorporation may be used for this purpose. 
With small quantities mixing can be accomplished by numerous 
sif tings and subsequent hand mixing; this method is ser- 
viceable for experimental laboratory mixtures. Mechanical 
mixers that are capable of mixing from 10 to 150 tons of 
fertilizer every 10 hours can be procured. 

44. Formulas for Fertilizer Mixtures. — Each manu- 
facturer has his own formula for making fertilizer. A few 
formulas will suffice to show the general method of com- 
bining the ingredients. For a fertilizer adapted for wheat and 
grass, the following mixture is prepared : 

Pounds 

Steamed bone 1,200 

Potassium chloride 45 

Filler ^55 

Total 2,000 



PACKING-HOUSE INDUSTRIES, PART 3 31 

An analysis of this mixture will be about as follows: 

Per Cent. 

Ammonia _ . 2 to 2.5 

Available phosphoric acid , 8 to 10.0 

, Potash 1 to 2.0 

Another mixture is as follows : 

Pounds 

Steamed bone 900 

Tankage (low grade) 190 

Potassium chloride 210 

Filler ^00 

Total 2,000 

An analysis of this is about as follows : 

Per Cent. 

Ammonia 2 to 3 

Available phosphoric acid 8 to 9 

Potash 5 to 6 

A mixture made for a potato fertilizer is compounded with 
the following ingredients : 

Pounds 

Steamed bone 1,000 

Sodium nitrate 212 

Tankage (low grade) 150 

Potassium chloride 365 

Filler 273 

Total 2,000 

This mixture will analyze as follows : 

Per Cent. 

Ammonia 4 to 5 

Available phosphoric acid 7 to 8 

Potash 9 to 10 

A so-called guano is made from the following fornrula : 

Pounds 

Steamed bone 570 

Sodium nitrate 200 

Tankage 900 

Potassium chloride 330 

Total , 2,000 



32 PACKING-HOUSE INDUSTRIES, PART 3 

This mixture makes a very high-grade fertiHzer containing 
no filler. It analyzes about as follows : 

Per Cent. 

Ammonia 6 to 7 

Available phosphoric acid 5 to 6 

Potash , 8 to 9 

A mixture composed of 

Pounds 

Bone meal 400 

Dissolved bone black , 400 

Dried blood 300 

Sodium nitrate 200 

Dissolved phosphate rock 350 

Potassium chloride 350 

Total 2,000 

was found to give on analysis 

Per Cent. 

Nitrogen 4.09 

Available phosphoric acid 9.59 

Insoluble phosphoric acid 2.50 

Potash 9.62 

Most fertilizers are sold under their special brand and their 
makers' names, and nearly all states in the United States 
have stringent laws governing the sale of fertilizer. These 
laws require that licenses be procured, registration of brands 
be made, analysis of the material be submitted, etc. They 
also require that a statement as to the guaranteed analysis 
be printed on the bags in which the material is sold. 



PACKING-HOUSE INDUSTRIES, PART 3 33 



ANALYTICAL METHODS AND TESTS OF 
PRODUCTS 



DETERMINATION OF GRADE OF OILS, TALLOWS, 
GREASES, ETC. 

45. The following analyses and tests, together with those 
referred to in Quantitative Analysis on the analysis of fats 
and also those on the examination of fertilizers, cover the most 
important methods used in packing-house laboratories. 

46. Determination of Free Fatty Acids in Oils, 
Tallows, Etc. — To ascertain the amount of free fatty acids 
in oils, etc., a supply of neutralized alcohol is made by dis- 
solving in ordinary alcohol a small quantity of phenolphthalein 
and cautiously adding drop by drop a weak solution of alkali 
until after persistent shaking the alcohol retains a faint pink 
color. All free acid is now neutralized. 

A known weight of oil or fat is placed in an ordinary 
4-ounce sample bottle and to it is added 50 or 60 cubic centi- 
meters of the neutralized alcohol. The whole is then shaken 
and heated on the water bath for 15 to 20 minutes or until 
hot. If the sample is wholly free from acid the pink color 
of the alcohol remains unchanged. If free acid is present 
the alcohol remains decolorized. A half-normal solution 
of caustic soda is now carefully added until after successive 
shakings the pink color returns to the alcoholic solution. The 
reaction is very sharp and the end point, with all material 
except very dark oils or greases, is well defined. When test- 
ing the latter a much larger quantity of alcohol is used and the 
solution after each shaking is allowed to settle. In this way 
the color of the underlying solution may more easily be 
observed. 

392-11 



34 PACKING-HOUSE INDUSTRIES, PART 3 

In ordinary practice, it is customary to consider the free 
acid present in oils and fats as oleic acid, although this may 
not actually be the case. The molecular weights of oleic and 
stearic acids do not differ so widely that the result is mate- 
rially affected. For example, 1 cubic centimeter of half- 
normal caustic solution corresponds to .142 gram of stearic 
acid or to .141 gram of oleic acid. 

For oils of average grade, 10 grams is usually taken for 
the test. For material containing very little free acid, the 
quantities taken for the test must be correspondingly increased 
to obtain an accurate result. For poor tallows, from 20 to 
25 grams is generally taken. For good tallows and oleo 
stearins, 50 grams is taken for the test. 

47. Determination of tlie Titer of a Fat. — The 
titer of a fat is the temperature, expressed in degrees centi- 
grade, at which the free fatty acids, extracted from that fat, 
will solidify. The determination of the titer requires first of 
all that the fatty acids be obtained free from the glycerine, 
combined with which they form, as glycerides, the bulk of the 
fat. In order to obtain the free fatty acids it is necessary to 
follow a roundabout method, as it is impossible to separate 
the fatty acids from the glycerine directly, except by subjecting 
the fat to a degree of heat and pressure and the action of a 
relatively smaller quantity of chemicals which are liable to 
cause changes in the free fatty acids. 

When an animal fat is treated and heated with a sufficient 
quantity of a strong alkali, as caustic soda or caustic potash, 
the glycerides are decomposed ; the alkali unites with the free 
fatty acids, forming soap and liberating the glycerine. The 
soap formed, when treated with a mineral acid such as hydro- 
chloric or sulphuric acid, is decomposed. The hydrochloric or 
sulphuric acid combining with the alkali of the soap leaves the 
free fatty acid as an oily layer on top of the hot aqueous 
solution of the other constituents. To separate this oily layer 
the aqueous solution may be drawn off from beneath the fatty 
acid or the entire mass may be cooked, when the fatty acids 
will congeal, forming a solid cake which can be removed from 



PACKING-HOUSE INDUSTRIES, PART 3 35 

the aqueous solution. By washing the free fatty acids with 
distilled water the adhering traces of mineral acid, etc. are 
removed ; by a subsequent drying all the adhering water is 
removed and the fatty acids are obtained free from any of 
the substances originally combined with or added to them in 
the course of separation. 

48. It is absolutely necessary to extract all the fatty acids 
from the fat and to have no fatty acids in combination with 
glycerine left in the free fatty acids, the solidifying tempera- 
ture of which is to be determined. In order to be sure that 
no such glycerides remain mixed with the fatty acids, it is 
necessary to saponify the fat completely ; that is, to unite all 
the fatty acids existing in the fat with the alkali. To insure 
and facilitate the completeness of saponification, alcohol is 
added when the fat is heated with the strong caustic alkali. 
The presence of alcohol accelerates the action of the caustic, 
and under proper conditions insures complete saponification. 
The alcohol may, however, cause an error if it is not completely 
removed by evaporation before the soap formed is decomposed 
by mineral acid. If alcohol is present in the soap when the 
mineral acid is added, the free fatty acid may combine with 
such alcohol and form a substance that, mixed with the free 
fatty acid, will reduce the solidifying temperature of the fatty 
acid. 

Any glycerides left in the fatty acids will have the same 
eflfect. It is therefore absolutely necessary to obtain complete 
saponification and to drive ofif all the alcohol from the soap 
formed before such soap is decomposed by a stronger acid. 
When with the exception of water the fatty acids are separated 
from all the other substances, there only remains the freeing 
of the fatty acids from the water before they can be tested 
for their solidifying point. It has been demonstrated that the 
manner in which this water is removed may materially influence 
the solidifying point. The titer is .5° higher when the fatty 
acids are previously heated for 2 hours at 100° C. than when 
such heating is not done, or done only for a considerably 
shorter time. 



Z6 PACKING-HOUSE INDUSTRIES, PART 3 

49. The method of determining the titer, as well as all 
other methods of fat and oil analysis, unless otherwise specified, 
are those following, adopted as ofificial by the American Chem- 
ical Society, on April 14, 1919, as a result of the report of the 
Committee on Analysis of Commercial Eats and Oils of the 
Division of Industrial Chemists and Chemical Engineers of this 
society : 

Fifty grams of fat are saponified with 60 cubic centimeters of a 
solution of 2 parts of methyl alcohol to 1 of 50 per cent. NaOH. The 
soap is dried, pulverized, and dissolved in 1,000 cubic centimeters of 
water in a porcelain dish and then decomposed with 25 cubic centi- 
meters of 75 per cent, sulphuric acid. The fatty acids are boiled until 
clear oil is formed and then collected and settled in a 150-cubic centi- 
meter beaker and filtered into a 50-cubic centimeter beaker. They are 
then heated to 130° C. as rapidly as possible with stirring, and trans- 
ferred, after they have cooled somewhat, to the usual V'XA" titer 
tube, placed in a 16-ounce bottle of clear glass, fitted with a cork 
that is perforated so as to hold the tube rigidly when in position. 
Suspend the titer thermometer so that it can be used as a stirrer 
and stir the fatty acids slowly (about 100 revolutions per minute) until 
the mercury remains stationary for 30 seconds. Allow the thermometer 
to hang quietly with the bulb in the center of the tube and report the 
highest point to which the mercury rises as the titer of the fatty acids. 
The titer should be made at about 20° C. for all fats having a titer 
above 30° C. and at 10° C. below the titer for all other fats. Any con- 
venient means may be used for obtaining a temperature of 10° below 
the titer of the various fats. The committee recommends first of all a 
chill room for this purpose; second, an artificially chilled small cham- 
ber with glass window ; third, immersion of the bottle in water or 
other liquid of the desired temperature. 

Standard Thermometer 
The thermometer is graduated at zero and in tenth degrees from 
10° C. to 65° C, with one auxiliary reservoir at the upper end and 
another between the zero mark and the 10° mark. The cavity in the 
capillary tube between the zero mark and the 10° mark is at least 
1 centimeter below the 10° mark, the 10° mark is about 3 or 4 centi- 
meters above the bulb, the length of the thermometer being about 
Z7 centimeters over all. The thermometer has been annealed for 
75 hours at 450° C. and the bulb is of Jena normal 16"' glass, or its 
equivalent, moderately thin, so that the thermometer will be quick- 
acting. The bulb is about 3 centimeters long and 6 millimeters in 
diameter. The stem of the thermometer is 6 millimeters in diameter 
and made of the best thermometer tubing with scale etched on the 



PACKING-HOUSE INDUSTRIES, PART 3 Z7 

stem, the graduation is clear-cut and distinct but quite fine. The 
thermometer must be certified by the United States Bureau of Standards. 

50. Determination of Moisture and Volatile Mat- 
ter. — The vacuum oven, which is an important piece of 
apparatus m the process of determining the moisture and 
volatile matter content of commercial fats and oils, is the 
Committee Standard Oven, a brief description of which is 
herewith appended : 

The standard oven has been designed with the idea of affording a 
simple and compact vacuum oven which will give as uniform tempera- 
tures as possible on the shelf. It consists of an iron casting of 
rectangular sections with hinged front door made tight by means of a 
gasket and which can be lowered on opening the oven so as to form 
a shelf on which samples may be rested. The oven contains but one 
shelf which is heated from above as well as below by means of 
resistance coils. Several thermometer holes are provided in order 
to ascertain definitely the temperature at different points on the shelf. 
Larger ovens containing more than one shelf have been tried by the 
committee, but have been found to be lacking in temperature uniform- 
ity and means of control. The entire oven is supported by means of a 
4-inch standard pipe which screws into the base of the oven and which 
in turn is supported by being screwed into a blind flange of suitable 
diameter which rests on the floor or work table. 

The standard moisture dish used shall be a shallow, glass dish, lipped, 
beaker form, approximately 6 to 7 centimeters in diameter and 4 centi- 
meters deep. 

Weigh out 5 grams of the prepared sample into a moisture 
dish. Dry to constant weight in vacuo at a uniform temperature not 
less than 15° C. nor more than 20° C. above the boiling point of water 
at the working pressure, which must not exceed 100 millimeters of 
mercury. Constant weight is attained when successive dryings for 
1-hour periods show an additional loss of not more than .05 per cent. 
The loss in weight is of moisture and volatile matter.^ 

The vacuum-oven method cannot be considered accurate in the case 
of fats of the coconut oil group containing free acid and the committee 
recommends that it be used only for oils of this group when they con- 
tain less than 1 per cent, free acid. In the case of oils of this group 
containing more than 1 per cent, free acid, recourse should be had 



^Results comparable to those of the Standard Method may be obtained on 
most fats and oils by drying 5-gram portions of the sample prepared and weighed 
as above, to constant weight in a well-constructed and well-ventilated air 
oven held uniformly at a temperature of 105° to 110° C. The thermometer bulb 
should be close to the sample. The definition of constant weight is the same as 
for the Standard Method. 



38 PACKING-HOUSE INDUSTRIES, PART 3 

temporarily to the routine control method for moisture and volatile 
matter^ until the committee develops a more satisfactory method. 

The air-oven method cannot be considered even approximately 
accurate in the case of the drying and semi-drying oils and those of the 
coconut oil group. Therefore, in the case of such oils as cottonseed 
oil, maize oil (corn oil), soy bean oil, linseed oil, coconut oil, palm 
kernel oil, etc., the vacuum-oven method should always be used except 
in the case of fats of the coconut group containing more than 1 per 
cent, free acid, as noted above. 

Insoluble Impurities 

Dissolve the residue from the moisture and volatile matter deter- 
mination by heating it on a steam bath with 50 cubic centimeters of 
kerosene. Filter the solution through a Gooch crucible properly pre- 
pared with asbestos, wash the insoluble matter five times with 
10-cubic centimeter portions of hot kerosene, and finally wash the 
residual kerosene out thoroughly with petroleum ether. Dry the cruci- 
ble and contents to constant weight as in the determination of moisture 
and volatile matter and report results as insoluble impurities. 

This determination, the title for which was adopted after careful 
consideration, determines the impurities which have generally been 
known as dirt, suspended matter, suspended solids, foreign solids, 
foreign matter, etc., in the past. The first solvent recommended by 
the committee is hot kerosene to be followed by petroleum ether kept at 
ordinary room temperature. Petroleum ether, cold or only slightly 
warm, is not a good fat and metallic soap solvent, whereas hot kerosene 
dissolves these substances readily, and for this reason the committee 
has recommended the double solvent method so as to exclude metallic 
soaps which are determined below as soluble mineral matter. 

Soluble Mineral Matter 
Place the combined kerosene filtrate and kerosene washings from the 
insoluble impurities determination in a platinum dish. Place in this an 
ashless filter paper folded in the form of a cone, apex up. Light the 



^The following method is suggested by the committee for routine control 
work: Weigh out 5- to 25-gram portions of prepared sample into a glass or 
aluminum {Caution: Aluminum soap may be formed) Leaker or casserole 
and heat on a heavy asbestos board over burner or hot plate, taking care that 
the temperature of the sample does not go above 130° C. at any time. During 
the heating rotate the vessel gently on the board by hand to avoid sputtering 
or too rapid evolution of moisture. The proper length of time of heating is 
judged by absence of rising bubbles of steam, by the absence of foam or by 
other signs known to the operator. Avoid overheating of sample as indicated 
by smoking or darkening. Cool in desiccator and weigh. 

By coojierative work in several laboratories, the committee has demonstrated 
that this method can be used and satisfactory results obtained on coconut oil 
even when a considerable percentage of free fatty acids is present, and the 
method is recommended for this purpose. Unfortunately on account of the 
very great personal factor involved, the committee cannot establish this method 
as a preferred method. Nevertheless, after an operator has learned the technique 
of the method, it gives perfectly satisfactory results for ordinary oils and fats, 
butter, oleomargarine, and coconut oil, and deserves more recognition than it 
has heretofore received. 



PACKING-HOUSE INDUSTRIES, PART 3 39 

apex of the cone, whereupon the bulk of the kerosene burns quietly. Ash 
the residue in a muffle, to constant weight, taking care that the decom- 
position of alkaline earth carbonates is complete, and the result will be 
the soluble mineral matter/ When the percentage of soluble mineral 
matter amounts to more than .1 per cent., multiply the percentage by 
10 and add this amount to the percentage of free fatty acids as 
determined.^ 

Soluble mineral matter represents mineral matter combined with 
fatty acids in the form of soaps in solution in the fat or oil. Formerly 
this mineral matter was often determined in combination by weighing 
the separated metallic soap or by weighing it in conjunction with the 
insoluble impurities. Since the soaps present consist mostly of lime 
soap, it has been customary to calculate the lime present therein by 
taking .1 the weight of the total metallic soaps. The standard method 
as given above is direct and involves no calculation. The routine 
method given in the note has been placed among the methods, although 
not adopted as a standard method for the reason that it is in use in some 
laboratories regularly. It should be pointed out, however, that the 
method cannot be considered accurate. 

Determination of Unsaponifiable Matter 

To find the content of unsaponifiable matter, the extraction cylinder 
used shall be glass-stoppered, graduated at 40 cubic centimeters, 80 cubic 
centimeters, and 130 cubic centimeters, with a diameter of about 
If inches, and a height of about 12 inches. Redistilled petroleum ether, 
boiling under 75° C, shall be used as a reagent. A blank must be made 
by evaporating 250 cubic centimeters with about .25 gram of stearin 
or other hard fat (previously brought to constant weight by heating) 
and drying as in the actual determination. The blank must not exceed 
a few milligrams. 

Method of Procedure 

Weigh 5 grams of the prepared sample into a 200-cubic centimeter 
Erlenmeyer flask, add 30 cubic centimeters of redistilled 95 per 
cent, (approximately) ethyl alcohol and 5 cubic centimeters of 
50 per cent, aqueous potassium hydroxide, and boil the mixture for 
1 hour under a reflux condenser. Transfer to the extraction cylinder 
and wash to the 40-cubic centimeter mark with redistilled 95 per cent, 
ethyl alcohol. Complete the transfer, first with warm then with cold 
water, till the total volume amounts to 80 cubic centimeters. Cool the 



iFor routine work, an ash may be run on the original fat, and the soluble 
mineral matter obtained by deducting the ash on the insoluble impurities from 
this. In this case the Gooch crucibile should be prepared with an ignited 
asbestos mat so that the impurities may be ashed directly after being weighed. 
In all cases ignition should be to constant weight so as to insure complete 
decomposition of carbonates. 

2See note on Soluble Mineral Matter following these methods. When 
the ash contains phosphates the factor 10 cannot be applied, but the bases con- 
sisting of calcium oxide, etc., must be determined, and the factor 10 applied to 
them. 



40 PACKING-HOUSE INDUSTRIES, PART 3 

cylinder and contents to room temperature and add 50 cubic centimeters 
of petroleum ether. Shake vigorously for 1 minute and allow to settle 
until both layers are clear, when the volume of the upper layer should 
be about 40 cubic centimeters. Draw off the petroleum ether layer as 
closely as possible by means of a slender glass siphon into a separatory 
funnel of 500 cubic centimeters capacity. Repeat extraction at least 
four more times, using 50 cubic centimeters of petroleum ether each 
time. Wash the combined extracts in a separatory funnel three times 
with 25-cubic centimeter portions of 10 per cent, alcohol, shaking vigor- 
ously each time. Transfer the petroleum ether extract to a wide-mouth 
tared flask or beaker, and evaporate the petroleum ether on a steam 
bath in an air-current. Dry as in the method for moisture and volatile 
matter. Any blank must be deducted from the weight before cal- 
culating unsaponifiable matter. Test the final residue for solubility in 
50 cubic centimeters petroleum ether at room temperature. Filter and 
wash free from the insoluble residue, if any, evaporate and dry in the 
same manner as before. The committee wishes to emphasize the neces- 
sity of thorough and vigorous shaking in order to secure accurate 
results. The two phases must be brought into the most intimate con- 
tact possible, otherwise low and disagreeing results may be obtained. 
When the unsaponifiable matter runs over 5 per cent, more extractions 
are recommended. 

The committee has considered unsaponifiable matter to include those 
substances frequently found dissolved in fats and oils which are not 
saponified by the caustic alkalies and which at the same time are soluble 
in the ordinary fat solvents. The term includes such substances as the 
higher alcohols, such as cholesterol which is found in animal fats, 
phytosterol found in some vegetable fats, paraffin and petroleum oils, 
etc. Unsaponifiable matter should not be confused in the lay mind with 
insoluble impurities or soluble mineral matter. 

Determination of Melting Point 

To determine the melting point, capillary tubes made from thin- 
walled glass tubing with an inside diameter of 5 millimeters drawn out 
to 1 millimeter inside diameter are used. The length of capillary part 
of tubes is to be about 5 centimeters. The length of the tube over all 
is to be 8 centimeters. In addition, a standard thermometer graduated 
in tenths of a degree and a 600-cubic centimeter beaker are necessary. 
The sample should be clear when melted and entirely free from mois- 
ture, or incorrect results will be obtained. 

Melt and thoroughly mix the sample. Dip three of the capillary 
tubes above described in the oil so that the fat in the tube stands 
about 1 centimeter in height. Now fuse the capillary end carefully 
by means of a small blast flame and allow to cool. These tubes are 
placed in a refrigerator overnight at a temperature of from 40° to 
50° F. They are then fastened by means of a rubber band or other 



PACKING-HOUSE INDUSTRIES, PART 3 41 

suitable means to the bulb of a thermometer graduated in tenths of a 
degree. The thermometer is suspended in a beaker of water (which is 
agitated by air or other suitable means) so that the bottom of the 
bulb of the thermometer is immersed to a depth of about 3 centimeters. 
The temperature of the water is increased gradually at the rate of 
about 1° per minute. 

The point at which the sample becomes opalescent is first noted and 
the heating continued until the contents of the tube become uniformly 
transparent. The latter temperature is reported as the melting point. 

Before finally melting to a perfectly clear fluid, the sample becomes 
opalescent and usually appears clear at the top, bottom, and sides before 
becoming clear at the center. The heating is continued until the con- 
tents of the tube become uniformly clear and transparent. This tem- 
perature is reported as the melting point. It is usually only a fraction 
of a degree above the opalescent point noted. The thermometer 
should be read to the nearest -h° C, and in addition this temperature may 
be reported to the nearest degree Fahrenheit if desired. 

A melting point is the temperature at which a solid substance assumes 
the liquid condition. If the solid is a pure substance in the crystalline 
condition the melting point is sharp and well defined for any given 
pressure. With increased pressure the melting point is lowered or 
raised, depending on whether the substance contracts or expands in 
melting. The lowering or raising of the melting point with pressure is 
very slight and ordinarily is not taken into consideration. Melting- 
point determinations are commonly carried out under ordinary atmos- 
pheric pressures without correction. The general effect of soluble 
impurities is to lower the melting point, and this holds true whether 
the impurity has a higher or lower melting point than the pure sub- 
stance (solvent). Thus if a small amount of stearic acid be added to 
liquid palmitic acid and the solution frozen, the melting point of this 
solid will be lower than that of palmitic acid. Likewise the melting 
point of stearic acid is lowered by the addition of a small amount of 
palmitic acid. 

The presence of water, especially when this is thoroughly mixed or 
emulsified with a fat or oil, influences the melting point to a marked 
extent, causing the mixture to melt through a longer range of 
temperatures than would be the case if the water were absent. This is 
particularly true of emulsified fats and oils, such as butter and oleomar- 
garine, both of which contain, besides water, the solids naturally present 
in milk or cream and including casein, milk sugar, and salts. The 
melting-point method recommended by the committee is not applicable 
to such emulsions or other watery mixtures and the committee has 
found it impossible to devise an accurate method for making softening- 
point or melting-point determinations on products of this nature. Not 
only the amount of water present but also the fineness of its particles, 
that is, its state of subdivision and distribution, in a fat or oil influences 



42 PACKING-HOUSE INDUSTRIES, PART 3 

the softening point or melting point and causes it to vary widely in 
different samples. 

As a consequence of the foregoing facts, natural fats and oils do 
not exhibit a definite melting point, composed as they are of mixtures 
of various crystalline glycerides, higher alcohols, fatty acids, and non- 
crystalline substances. Therefore, the term melting point when applied 
to them requires further definition. They exhibit first a lower melting 
point (the melting point of the lowest melting component) or what 
might be called the softening point, and following this the fat softens 
through a shorter or longer range of temperature to the final melting 
point at which temperature the fat is entirely liquid. This is the melt- 
ing point determined by the committee's melting-point method. The 
range between the softening point and the final melting point varies 
greatly with the different fats and oils depending on their chemical 
components, the water associated with them, emulsification, etc. In 
the case of coconut oil the range between softening point and final 
melting point is rather short; in the case of butter, long. Various 
methods have been devised to determine the so-called melting point of 
fats and oils. Most of these methods, however, determine, not the 
melting point, but the softening point or the flow point of the fat and 
the great difficulty has been in the past to devise a method which would 
determine even this point with reasonable accuracy and so that results 
could be easily duplicated. It has been the aim of the committee to 
devise a simple method for the determination of the melting point of 
fats and oils, but it should be understood that the term melting point 
in the scientific sense is not applicable to natural fats and oils. 

Determination of Iodine Number (Wijs Method) 

Preparation of Reagents : The iodine solution is prepared by dis- 
solving 13 grams of resublimed iodine in one liter of C. P. glacial 
acetic acid and passing in washed and dried chlorine gas until the 
original thiosulphate titration of the solution is not quite doubled. The 
solution is then preserved in amber glass-stoppered bottles sealed with 
paraffin until ready for use. 

Mark the date, on which the solution is prepared, on the bottle or 
bottles and do not use if it is more than 30 days old. 

There should be no more than a slight excess of iodine, and no 
excess of chlorine. When the solution is made from iodine and 
chlorine, this point can be ascertained by not quite doubling the 
titration.^ 



^P. C. Mcllhiney, /. Am. Chem. Soc, 29 (1917), 1222, gives the following details 
for the preparation of the iodine-monochloride solution: 

The preparation of the iodine-monochloride solution presents no great diffi- 
culty, but it must be done with care and accuracy in order to obtain satisfactory 
results. There must be in the solution no sensible excess either of iodine or 
more particularly of chlorine, over that required to form the monochloride. This 
condition is most satisfactorily attained by dissolving in the whole of the acetic 
acid to be used the requisite quantity of iodine, using a gentle heat to assist the 



PACKING-HOUSE INDUSTRIES, PART 3 43 

The glacial acetic acid used for preparation of the Wijs iodine solu- 
tion should be of 99 to 99.5 per cent, strength. In case of glacial acetic 
acids of somewhat lower strength, the committee recommends freezing 
and centrifuging o draining as a means of purification. 

A^/10 Sodium Thiosulphate Solution : Dissolve 24.8 grams of C. P. 
sodium thiosulphate in recently boiled distilled water and dilute with the 
same to 1 liter at the temperature at which the titrations are to be 
made. 

Starch Paste: Boil 1 gram of starch in 200 cubic centimeters of 
distilled water for 10 minutes and cool to room temperature. 

Potassium Iodide Solution: Dissolve 150 grams of potassium iodide 
in water and make up to 1 liter. 

A^/10 Potassium Bichromate : Dissolve 4.903 grams of C. P. potas- 
sium bichromate in water and make the volume up to 1 liter at the 
temperature at which titrations are to be made. 

Standardization of the Sodium Thiosulphate Solution : Place 40 cubic 
centimeters of the potassium bichromate solution, to which has been 
added 10 cubic centimeters of the solution of potassium iodide, in a 
glass-stoppered flask. Add to this 5 cubic centimeters of strong hydro- 
chloric acid. Dilute with 100 cubic centimeters of water, and allow 
the N/10 sodium thiosulphate to flow slowly into the flask until the 
yellow color of the liquid has almost disappeared. Add a few drops of 
the starch paste, and with constant shaking continue to add the N/10 
sodium thiosulphate solution until the blue color just disappears. 

Determination 
Weigh accurately from .10 to .50 gram (depending on the iodine 
number) of the melted and filtered sample into a clean, dry, 16-ounce 
glass-stoppered bottle containing 15-20 cubic centimeters of car- 
bon tetrachloride or chloroform. Add 25 cubic centimeters of iodine 
solution from a pipette, allowing to drain for a definite time. The 
excess of iodine should be from 50 per cent, to 60 per cent, of the 
amount added, that is, from 100 per cent, to 150 per cent, of the amount 
absorbed. Moisten the stopper with a 15 per cent, potassium-iodide 
solution to prevent loss of iodine or chlorine, but guard against an 
amount sufficient to run down inside the bottle. Let the bottle stand 
in a dark place for i hour at a uniform temperature. At the end of 
that time add 20 cubic centimeters of 15 per cent, potassium-iodide 
solution and 100 cubic centimeters of distilled water. Titrate the iodine 
with N/10 sodium thiosulphate solution which is added gradually, with 

solution, if it is found necessary, setting aside a small portion of this solution, 
while pure and dry chlorine is passed into the remainder until the halogen con- 
tent of the whole solution is doubled. Ordinarily it will be found that by pass- 
ing the chlorine into the main part of the solution until the characteristic color 
of free iodine has just been discharged there will be a slight excess of chlorine 
which is corrected by the addition of the requisite amount of the unchlorinated 
portion until all free chlorine has been destroyed. A slight excess of iodine does 
little or no harm but excess of chlorine must be avoided. 



44 PACKING-HOUSE INDUSTRIES, PART 3 

constant shaking, until the yellow color of the solution has almost dis- 
appeared. Add a few drops of starch paste and continue titration until 
the blue color has entirely disappeared. Toward the end of the reaction 
stopper the bottle and shake violently so that any iodine remaining in 
solution in the tetrachloride or chloroform may be taken up by the 
potassium-iodide solution. Conduct two determinations on blanks 
which must be run in the same manner as the sample except that no 
fat is used in the blanks. Slight variations in temperature quite 
appreciably affect the titer of the iodine solution, as acetic acid has a 
high coefficient of expansion. It is, therefore, essential that the blanks 
and determinations on the sample be made at the same time. The 
number of cubic centimeters of standard thiosulphate solution required 
by the blank, less the amount used in the determination, gives the thio- 
sulphate equivalent of the iodine absorbed by the amount of sample used 
in the determination. Calculate to centigrams of iodine absorbed by 
1 gram of sample (= per cent, iodine absorbed). 
Iodine Number, Tung Oil 

The committee has made an extensive study of the application of 
the Wijs method to the determination of iodine value in the case of 
tung oil, with the result that it recommends the method for this oil 
but has thought it desirable to Hmit the conditions under which the 
determination is conducted rather narrowly, although reasonably good 
results are obtained by the committee method without making use of 
the special limitations. 

The cooperative work of the committee and the special investigations 
conducted by individual members bring out the following points : 

Influence of Temperature: From 16° C. to 30° C. there is a 
moderate increase in the absorption of iodine, but above 30° the 
increase is rather rapid so that it was thought best to limit the tempera- 
ture in the case of tung oil to 20° to 25° C. 

Influence of Time : The absorption increases with the time, but 
apparently complete absorption, so far as unsaturated bonds are con- 
cerned, occurs well within 1 hour's time. Consequently, 1 hour was 
set as the practical limit. 

Influence of Age of Solution: Old solutions tend to give low results, 
although up to 2 months no great differences were observed. Never- 
theless, it was thought best to limit the age of the solution to 30 days 
— long enough for all practical purposes. 

Saponification Number 

With reference to the saponification (Koettstorfer) number, the 
method of preparation of the reagents is as follows : 

N /2 hydrochloric acid, carefully standardized. 

Alcoholic Potassium Hydroxide Solution : Dissolve 40 grams of 
pure potassium hydroxide in 1 liter of 95 per cent, redistilled alcohol 
(by volume). The alcohol should be redistilled from potassium 



PACKING-HOUSE INDUSTRIES, PART 3 45 

hydroxide over which it has been standing for some time or with which 
it has been boiled for some time, using a reflux condenser. The solu- 
tion must be clear and the potassium hydroxide free from carbonates. 
Determination 
Weigh accurately about 5 grams of the filtered sample into a 250- to 
300-cubic centimeter Erlenmeyer flask. Pipette 50 cubic centimeters 
of the alcoholic potassium hydroxide solution into the flask, allowing 
the pipette to drain for a definite time. Connect the flask with an air 
condenser and boil until the fat is completely saponified (about 30 min- 
utes). Cool and titrate with the N /2 hydrochloric acid, using 
phenolphthalein as an indicator. Calculate the Koettstorfer number 
(milligrams of potassium hydroxide required to saponify 1 gram of fat). 
Conduct two or three blank determinations, using the same pipette and 
drainage for the same length of time as above. 

51. To determine the melting point of fats Wiley's 
method has been adopted as official by the Association of 
Official Agricultural Chemists. It is based on the fact that a 
disk of fat when in suspension in a liquid assumes a spheroidal 
form when melted. The method is described by Wiley as 
follows : 

In the preparation of the apparatus there are required (1) a 
piece of ice floating in distilled water that has been recently 
boiled and (2) a mixture of alcohol and water of the same 
specific gravity as the fat to be examined. This is prepared 
by boiling distilled water and 95 per cent, alcohol for 10 min- 
utes, to remove the gases that they may hold in solution. 
While still hot the water is poured into a test tube, described 
later, until it is almost half full. The test tube is then nearly 
filled with the. hot alcohol, which is carefully poured down the 
side of the inclined tube to avoid too much mixing. If the 
alcohol is not added until the water has cooled, the mixture will 
contain so many air bubbles as to render it unfit for use. 
These bubbles will gatheron the disk of fat as the temperature 
rises and finally force it to the top. 

52. The apparatus for determining the melting point is 
shown in Fig. 7, and consists of an accurate thermometer a, 
for determining the melting point, reading easily tenths of a 
degree (it is advisable to use a cathetometer for reading the 
thermometer, but this may be done with an eye glass if held 



46 



PACKING-HOUSE INDUSTRIES, PART 3 



steadily and properly adjusted) ; a thermometer c for regula- 
ting the temperature of the bath; a test tube d 35 centimeters 
high and 10 centimeters in diameter; a test tube e 30 centi- 
meters long and 3J centimeters in diameter ; a stand / for sup- 
porting the apparatus; and 
some device for stirring the 
water in the test tube (for 
example, a blowing bulb g 
of rubber and a bent glass 
tube extending almost to the 
bottom of the test tube). 

The disks of fat are pre- 
pared as follows : The melted 
and filtered fat is allowed to 
fall from a dropping tube, 
from a height of about 20 
centimeters, on a smooth 
piece of ice floating in re- 
cently boiled distilled water. 
The disks* thus formed are 
from 1 to IJ centimeters in 
diameter and weigh, about 
200 milligrams. By pressing 
the ice under the water the 
disks are made to float on 
the surface, from which they 
are easily removed with a 
steel spatula, which should 
be cooled in the ice water 
before using. The disks 
must be allowed to stand 
for 2 or 3 hours in order to obtain the normal melting point. 




53. The test tube e containing the alcohol and water is 
placed in the test tube d containing water and ice and left there 
until cold. The disk of fat is then dropped into e from the 
spatula and at once sinks until it reaches a part of the tube 
where the density of the mixture of alcohol and water is 



PACKING-HOUSE INDUSTRIES, PART 3 47 

exactly equivalent to its own. Here the disk remains at rest 
and free from the action of any force save that inherent in its 
own molecules. 

The delicate thermometer a is placed in the test tube e and 
then lowered until the bulb is just above the disk. In order 
to secure an even temperature in all parts of the alcohol 
mixture, in the vicinity of the disk, the thermometer is gently 
moved from time to time in a circularly pendulous manner. 

The disk having been placed in position, the water in the 
the test tube d is slowly heated and kept constantly stirred by 
means of the blowing apparatus g already described. When the 
temperature of the alcohol-water mixture rises to about 6° C. 
below the melting point, the disk of fat begins to shrivel and 
it gradually rolls up into an irregular mass. 

54. The thermometer is now lowered until the particle of 
fat is even with the middle point of the bulb. The bulb d 
should be small, so as to indicate only the temperature of 
the mixture near the fat, and a gentle rotatory movement 
should be given to the thermometer bulb. The rise of tem- 
perature should be so regulated that the last 2° C. of incre- 
ment requires about 10 minutes. The mass of fat gradually 
approaches the form of a sphere and when it is sensibly so the 
reading of the thermometer should be made. When this has 
been done the tube is removed from the bath and again placed 
in the cooler. A second tube containing alcohol and water is 
at once placed in the bath. The test tube (ice water having 
been used as a cooler) is of low enough temperature to cool 
the bath sufficiently. After the first determination, which 
should be only a trial, the temperature of the bath should be 
so regulated as to reach a maximum of about 15° C. above the 
melting point of the fat under examination. 

The edge of the disk of fat should not be allowed to touch 
the sides of the tube. This accident rarely happens, but in 
case it should take place and the disk adheres to the sides of 
the tube, a new trial should be made. 

Triplicate determinations should be made, and the second 
and third results should agree closely. 



48 PACKING-HOUSE INDUSTRIES, PART 3 

In this connection, with the determination of melting points, 
the melting point of waxes in Quantitative Analysis should be 
referred to. The methods there described are also applicable 
in some cases to fats, but the method just explained has met 
with much success and approval. For rapid determinations 
with a large number of samples, however, the method of 
Hebner and Angell is to be preferred. 

55. Detection of Cottonseed Oil in Oils and Fats. 

The detection of cottonseed oil is often a matter of importance 
since its lower cost renders it a likely adulterant of other 
more expensive oils and fats. Of the various methods which 
have been proposed, the Halpen test has been chosen as 
standard, since it is more sensitive and capable of yielding 
more accurate results than the others. It is not affected by 
rancidity which is of great importance at times in a test. The 
depth of color is proportional to a certain extent to the 
amount of oil present, and by making comparative tests with 
cottonseed-oil mixtures of known proportions, some idea of 
the amount present in a mixture of oils under examination can 
be obtained. In should be remembered, however, that different 
oils react with different intensities, and cottonseed oils that 
have been heated to from 200° to 210° C. react with greatly 
diminished intensity. Heating 10 minutes at 250 C. renders 
cottonseed oil incapable of giving a reaction. 

Lard and lard oil from animals fed on cottonseed meal will 
give a faint reaction, as will also the fatty acids. 

The Halpen test is made as follows : Carbon bisulphide 
containing about 1 per cent, of sulphur in solution is mixed 
with an equal volume of amyl alcohol. Equal volumes of this 
reagent and the oil under examination are then mixed and 
heated in a bath of boiling saturated brine from 1 to 2 hours. 
In the presence of as small an amount as 1 per cent, of cotton- 
seed oil, an orange or a red color is produced, which is char- 
acteristic. 

In the Bechi, or silver-nitrate test for cottonseed oil, rancid 
oils or fats must first be purified before testing, a condition 
that Halpen's test does not require. 



PACKING-HOUSE INDUSTRIES, PART 3 49 

In connection with the two preceding tests, those described 
in Quantitative Analysis should also be applied. When any 
single test fails to give results of a most decisive character 
regarding adulteration, all tests applicable should be applied 
to the lard, fat, or oil under consideration. Taking all the 
results together, the absence or presence of cottonseed oil or 
other adulteration may be determined with comparative 
certainty. 

5G. Determination of Tallow in Lard. — It is fre- 
quently of importance to have a rapid method of ascertaining 
whether or not a lard is adulterated with beef fats. While a 
large proportion of the latter would be made evident to the prac- 
tical chemist by the altered physical characteristics of pure lard, 
yet an admixture of a small percentage of tallow or oleo 
stearin might easily pass unnoticed. 

57. A good method for determining small quantities of 
tallow is Wesson's method, which, while not exact in the 
scientific sense, is so eminently practical, rapid, and easily 
applicable in the packing house, that it is relied on to give 
approximate results. It is obvious that the results obtained 
by this method must be confirmed by further investigation, 
iodine number, etc., where the result is of importance in legal 
cases, disputes, etc., but for the matching or duplicating of lard 
for trade purposes other than domestic, the method has great 
value and utility. 

All fats in a state of fusion a little above their melting points, 
may be considered as solutions of their solid glycerides in the 
liquid oils or the oleins. For example, cottonseed oil at ordi- 
nary temperatures contains from 20 to 25 per cent, of solid 
glycerides, which crystallize out as stearin. When the oil is 
chilled and at a temperature of 0° C, the oil becomes a solid 
fat. In like manner, prime steam lard at 32° C. is a clear oil 
from which its solid glycerides crystallize on cooling until at 
25° C. the lard becomes solid fat. Prime steam lard contains 
about 35 per cent, of solid glycerides and about 65 per cent, 
of olein, which holds the glycerides in solution at 30° to 32° C, 
and in some instances lower. 

392-12 



50 PACKING-HOUSE INDUSTRIES, PART 3 

The solid glycerides from tallow are far less soluble in 
oleiii than those from lard and crystallize out at much higher 
temperatures. Owing to this fact, it is possible to detect with 
ease and certainty the solid glycerides of beef fat, namely, oleo 
stearin, when it exists in lard in quantities of 5 per cent, and 
upwards. 

58. Wesson's process, which is very simple, is carried out 
as follows : 

First, determine the titer of the fat under examination. The 
Dalican titer or crystallization temperature of the fatty acids 
indicates approximately the proportions of liquid and fluid 
acids present. 

Second, prepare with materials of known purity — prime lard 
and prime-lard stearin — a mixture that will possess about the 
same titer as the sample. Pour some of the melted standard 
into one test tube and a like quantity into another ; at the same 
time have another test tube that contains a mixture of lard 
hardened to the same titer with oleo stearin. All the tubes 
are now brought to the same temperaure in a beaker of hot 
water and immersed in a bath of water at about 35° C. As 
the bath cools down, the tubes are watched from time to time 
and the temperatures and times at which they deposit crystals 
and their manners of crystallization are noted. 

If the sample under examination consists of pure lard stock, 
it will cool in a manner similar to the standard mixture. If 
oleo stearin is present, the sample will deposit crystals, or 
become cloudy sooner and at a higher temperature than the 
standard, and comparison with the samples prepared with oleo 
stearin will show the approximate percentage, which will be 
confirmed by the Dalican titer, taking into consideration the 
approximate amount of cottonseed oil that may be present. 
The manner of cooling is quite characteristic. Pure lard stock 
generally forms comparatively large stellate, or starlike, 
bundles of crystals, while those from oleo stearin are very 
small, and appear as a cloud. A few trials with mixtures of 
known composition will make these appearances familiar and 
unmistakable. 



PACKING-HOUSE INDUSTRIES. PART 3 



51 



It is of the utmcxt importance that the lards should be dry 
and clear, as moisture will cause a lard to cloud above its 
normal temperature. With this test, soft tallow and oleo- 
margarine, having not too low melting and cooling points on 
account of the excess of olein in them, give the indications 
of quantities of oleo stearin proportional to their hardness; 
and in some cases 
where the flavor and 
appearance of the 
sample indicate tal- 
low rather than oleo 
stearin, it is the cus- 
tom to report tallow 
equivalent to so much 
oleo stearin. 

With lards of com- 
paratively high titer 
and consequently high 
cooling point, it is 
necessary to consider 
the effect of lard 
stearin on the titer 
when calculating the 
probable composition. 
Ten per cent, of oleo 
stearin mixed with pure lard will deposit crystals and show 
cloudiness before a mixture of 50 per cent, of lard and 50 per 
cent, of lard stearin. 




Fig. 



59. The arrangement of the apparatus used for this deter- 
mination is shown in Fig. 8. A beaker a having a capacity of 
about 750 cubic centimeters is covered with a piece of thin 
wood, cardboard, or metal c. This cover is provided with a 
circular aperture, through which passes a smaller beaker h. 
The cover c^ is provided with orifices for a number of test 
tubes /, which contain the samples and standards of compari- 
son. A thermometer t serves to indicate the temperature in the 
beaker h. The inner beaker h is filled with water up to the 



52 PACKING-HOUSE INDUSTRIES, PART 3 

point marked w, which should be a Httle above the surface zi/ 
of the melted lards. 

60. The A. O. A. C. method, which has been adopted 
by the Association of Official Agricultural Chemists, as tenta- 
tive, is much more accurate : 

Weigh out 5 grams of the filtered fat into a 25-cubic centi- 
meter glass-stoppered cylinder, graduated, and add warm 
acetone until the 25-cubic centimeter mark is reached. Shake 
the cylinder until the contents are thoroughly mixed ; then allow 
the cylinder and contents to stand in a suitable place in which 
a temperature of 30° C. is maintained. After 18 hours remove 
the cylinder and carefully decant the supernatant liquid from 
the crystallized glycerides, which are usually found in a firm 
mass at the bottom of the cylinder. Then add warm acetone 
in three portions of 5 cubic centimeters each from a small wash 
bottle, care being taken not to break up the deposit while wash- 
ing and decanting the first two portions. Agitate actively the 
third portion in the cylinder and, by a quick movement, trans- 
fer the same to a small filter paper. Wash the crystals with 
five successive small portions of the warm acetone by means 
of a wash bottle and remove the excess acetone by suction. 
Transfer the paper with its contents to a suitable place where 
it should be spread out and any large lumps of the glycerides 
broken up by gentle pressure. When dry thoroughly com- 
minute the mass and determine the melting point of the 
crystals. A melting point below 63° is regarded as evidence of 
adulteration and as suspicious. 

61. After the melting point of the crystallized glycerides 
has been determined, transfer them to a 50-cubic centimeter 
beaker, add 25 cubic centimeters of approximately N/2 
alcoholic potassium hydroxide and heat on the steam bath 
until saponification is complete. Pour the solution into a 
separatory funnel containing 200 cubic centimeters distilled 
water, acidify, add 75 cubic centimeters of ether, and shake. 
Draw off the acid layer and wash at least three times with 
distilled water. Transfer the ether solution to a clean dry 
50-cubic centimeter beaker, drive off the ether on the steam 



PACKING-HOUSE INDUSTRIES, PART 3 53 

bath and finally dry the acids at 100° C. After the acids have 
stood for at least 2 hours after drying, determine the melting 
point in the same manner in which the melting point of the 
crystals was determined. If the melting point of the glycerides 
plus twice the difference between the melting point of the 
glycerides and the melting point of the fatty acids is less than 
73° C, the lard is regarded as adulterated. 

62. The melting point of glycerides and fatty acids is to 
be determined in the following manner: A large test tube, 
approximately 150X35 millimeters containing water (free 
from air) into which the bulb of a thermometer (graduated 
in -J degrees from 1 to 100) with the melting-point tube 
attached is immersed, is placed in a beaker of water and so 
adjusted that the surface of the liquid contained in the two 
vessels is at the same level. The water in the beaker should be 
heated rapidly to about 50° C. and that temperature main- 
tained until the thermometer carrying the melting-point tube 
registers between 50° and 55°, then heat is again applied and 
the temperature of the outer bath carried somewhat rapidly 
to 67°, when the lump is removed. The melting point of the 
crystals is regarded as that point when the fused substance 
becomes perfectly clear and transparent. The use of a dark 
background placed about 4 inches from the apparatus will 
be of advantage. 

63. The melting-point tube should be of about 1 millimeter 
internal diameter, sealed at one end, with a slight flare at the 
other extremity in order that the loading may be expedited. 
The amount of the substance taken should be approximately 
the same for all the determinations and should occupy a space 
about 9 millimeters in length, being somewhat firmly packed 
in the lower end of the tube by tapping it sharply on a hard 
surface. The water in the outer bath should be agitated fre- 
quently during the determination. 

In the A. O. A. C. method there are several possible sources 
of error that must be carefully avoided. The fat must be 
filtered and free from dirt and moisture, as these may hinder 
proper crystallization. The crystal mass should be compact 



54 PACKING-HOUSE INDUSTRIES, PART 3 

and the crystallization not too rapid, as this may give rise to a 
larger mass of small fluffy crystals. The temperature should 
be as indicated if higher crystallization is not to take place. 
The crystals must be carefully washed to make sure that softer 
fats are not retained by the crystal mass. The fat must be 
completely in solution in the acetone before crystallization is 
allowed to proceed. 

64. Cold Test of Animal Oils. — The cold test is a trade 
requirement with most animal oils. The sample of oil must 
be thoroughly mixed, to insure uniformity. If the oil is frozen 
or chilled, it must be warmed and melted to a uniform con- 
sistency. The test is made as follows : 

About 1 ounce of the oil to be tested is put into a common 
4-ounce sample bottle, and in the oil is placed a short, stout 
thermomxCter. The bottle is then placed in a situation where 
the oil will become frozen; if necessary, a freezing mixture 
is used. (In connection with this test, see Quantitative 
Analysis under the heading Cloud Test in Mineral Oils.) 
When the liquid has become solid throughout, the bottle is 
removed from the cold and the oil allowed to soften. At the 
same time the oil is thoroughly stirred and mixed with the ther- 
mometer until the mass will run from one end of the 
bottle to the other. The neck of the bottle is now grasped 
by one hand, which should hold some waste or a towel to 
enclose the thermometer. The latter is withdrawn through 
the waste or towel, so as to wipe far enough to see the 
mercury, and the temperature is observed. The reading is the 
cold test of the oil. 



METHODS OF FERTILIZER ANALYSIS 

65. The following methods are those ordinarily used in 
the packing-house laboratory in the analysis of fertilizers and 
tankages. These methods have been adopted by the Associa- 
tion of Official Agricultural Chemists as the official methods 
to be used on such products. 

06. Determination of Moisture. — Heat 2 grams of the 
sample for 5 hours in a water oven at the temperature of 



PACKING-HOUSE INDUSTRIES, PART 3 55 

boiling water. In the case of potash saUs, sodium nitrate, 
and ammonium sulphate, heat at about 130° C. to constant 
weight. The loss in weight is considered as moisture. 

67. Preparation of Solutions. — The solutions used in 
the analysis of fertilizers are prepared as follows : 

Ammonmm Molybdafe Solution. — A solution of ammonium 
molybdate is prepared as follows: Dissolve 100 grams of 
molybdic acid in dilute ammonium hydroxide (144 cubic centi- 
meters of ammonium hydroxide and 271 cubic centimeters of 
water) ; pour this solution slowly and with constant stirring 
into dilute nitric acid (489 cubic centimeters of nitric acid and 
1,148 cubic centimeters of water). Keep the mixture in a 
warm place for several days. Decant the solution from any 
sediment and preserve in glass-stoppered bottles. 

Sodmm-Hydr oxide Solution. — This solution should be made 
up of such strength that 1 cubic centimeter is exactly equiva- 
lent to .001 gram of phosphorus pentoxide, Po^s- ^^ order to 
calculate the strength of this solution, the equation which repre- 
sents the reaction which takes place between sodium hydroxide 
and ammonium phosphomolybdate, is made use of. 

2(NH,),PO,(MoO,),,-\-46NaOH = 2(NH,),HPO^ 
+ {NH^)^MoO^-\-2?^Na^MoO^+22H.P 

From this equation it is seen that 46 molecules of sodium 
hydroxide correspond to 2 molecules of ammonium phospho- 
molybdate and since the latter also contains the equivalent of 
1 molecule of phosphorus pentoxide, 46 molecules of sodium 
hydroxide are equivalent to 1 molecule phosphorus pentoxide 
in the above reaction. 

The molecular weight of A6NaOH is 1840.368. 

The molecular weight of Pfi^ is 142.08. 

Then, 142.08 : .001 gram : : 1840.368 :X; X = .0129 gram 
NaOH equivalent to .001 gram of PzO^. 

Therefore, a solution should be made up; each cubic centi- 
meter of which contains .0129 gram NaOH. Thus 1,000 cubic 
centimeters would contain 12.9 grams NaOH. It is practically 
impossible to make up an accurate solution by weighing out this 
quantity of NaOH and dissolving it in water and diluting to 



56 PACKING-HOUSE INDUSTRIES, PART 3 

1,000 cubic centimeters, but if a normal solution of sodium 
hydroxide is at hand, it may be diluted to the required strength 
as follows : 

1 cubic centimeter — NaOH contains .04 gram NaOH 

Then, .04-^.0129 = 3.1, or if 1 cubic centimeter of normal 
sodium hydroxide solution is diluted to 3.1 cubic centimeters, 
the resulting solution will be of the required strength. 

Nitric- Acid Solution. — This solution should be of such 
strength that 1 cubic centimeter exactly equals 1 cubic 
centimeter of the sodium hydroxide solution. This is accom- 
plished by titrating a nitric acid solution of approximate 
strength against the standard sodium hydroxide solution, using 
phenolphthalein as an indicator. 

Phenol pJithalein Solution. — Dissolve 1 gram of phenol- 
phthalein in 100 cubic centimeters of alcohol. 

68. Determination of Phosphoric Acid. — Weigh 
out a 2-gram sample of the fertilizer in a 250-cubic centimeter 
volumetric flask, add 30 cubic centimeters of concentrated 
nitric acid and about 5 cubic centimeters of concentrated hydro- 
chloric acid and boil until the solution becomes clear, adding 
more nitric acid to replace that which boils away, if necessary. 
When the sample has dissolved, cool the solution to the tem- 
perature marked on the flask (usually 20° C.) and then dilute it 
to exactly 250 cubic centimeters with water at the same tem- 
perature. Now transfer 50 cubic centimeters (.4 gram) of this 
solution to an Erlenmeyer flask and neutralize it with 
ammonium hydroxide and then clear up the solution with a 
few drops of nitric acid. To the hot solution (about 60° C.) 
add from 30 to 50 cubic centimeters of ammonium molybdate 
solution. Shake for about 5 minutes, then allow the precipitate 
of ammonium phosphomolybdate to stand at about 60° C, for 
15 to 20 minutes. Filter and wash the precipitate free from all 
acid, with cold water. This will require from four to five 
washings. Now transfer the well-washed precipitate and paper 
to a beaker and dissolve the precipitate in a known quantity of 
sodium hydroxide solution (about 10 cubic centimeters) meas- 



PACKING-HOUSE INDUSTRIES, PART 3 57 

ured from a burette. Break up the filter paper in the beaker 
and add a few drops of phenolphthalein solution. Then titrate 
with the nitric acid solution. Subtract the number of cubic 
centimeters of nitric acid solution used, from the number of 
cubic centimeters of sodium hydroxide solution added. The 
difference represents the number of cubic centimeters of sodium 
hydroxide solution used in dissolving the precipitate. The 
number of cubic centimeters of sodium hydroxide solution so 
used, multiplied by .001 gives the number of grams of PoO^ in 
the sample. This result multiplied by 100 and divided by the 
weight of the sample taken (.4 gram) gives the per cent, 
of P,0,. 

69. Determination of Nitrogren. — The following 
reagents are used for the determination of nitrogen by the 
Kjeldahl method. 

Standard Acid: Half-normal sulphuric acid carefully stand- 
ardized : 

Standard Alkali : Half-normal sodium hydroxide solution. 

Sulphuric Acid: Specific gravity 1.84. Free from nitrates 
and ammonium sulphate. 

Metallic Mercury: Redistilled. 

Granulated Zinc : To prevent bumping. 

Potassium Sulphide Solution : Dissolve 40 grams in 1 liter 
of water. 

Sodium Hydroxide Solution: Saturated solution free from 
nitrates. 

Methyl Red : One gram in 100 cubic centimeters of 95 per 
cent, alcohol. 

To determine the amount of nitrogen, place .7 to 3.5 grams, 
according to the nitrogen content of the substance to be 
analyzed, in a digestion flask with approximately .7 gram 
metallic mercury and add 20 to 30 cubic centimeters of sul- 
phuric acid. Place the flask in an inclined position and 
heat below the boiling point of the acid until frothing has 
ceased. Then increase the heat until the acid boils briskly 
and digest for a time after the mixture is colorless or nearly so, 
or until oxidation is complete. 



58 PACKING-HOUSE INDUSTRIES, PART 3 

After cooling, dilute with about 200 cubic centimeters of 
water, add a few pieces of granulated zinc if necessary to 
prevent bumping, and 25 cubic centimeters of potassium 
sulphide solution with shaking. Next add sufficient sodium 
hydroxide solution to make the reaction strongly alkaline, 
50 cubic centimeters are usually enough, pouring it down the 
side of the flask so that it does not mix at once with the acid 
solution. Connect the flask with the condenser, mix the con- 
tents by shaking, distil until all ammonia has passed over into 
a measured quantity of the standard acid, and titrate with the 
standard alkali. The first 150 cubic centimeters of the dis- 
tillate will generally contain all of the ammonia. 

Previous to use, the reagents should be tested by a blank 
experiment with sugar. The sugar partially reduces any 
nitrate that might otherwise escape notice. 

70. Determination of Potash. — The following chemi- 
icals are employed to detect the presence of potash : 

Ammonium Chloride Solution : Dissolve 100 grams of 
ammonium chloride in 500 cubic centimeters of water, add 
5 to 10 grams of pulverized potassium platinic chloride and 
shake at intervals of 6 to 8 hours. Allow the mixture to settle 
overnight and filter. The residue may be used for the prepa- 
ration of a fresh supply. 

Platinum Solution: A platinic chloride solution containing 
the equivalent of 1 gram of metallic platinum (2.1 gram of 
H^PICIq) in every 10 cubic centimeters. 

Eighty Per Cent. Alcohol : Specific gravity .8593 at 20° C. 

To detect the presence of potash, place 2.5 grams of the 
sample upon a 12.5-centimeter filter paper and wash into a 
250-cubic centimeter flask with successive portions of boiling 
water until the filtrate amounts to about 200 cubic centimeters. 
Add to the hot solution a slight excess of ammonium hydroxide 
and sufficient ammonium oxalate to precipitate all of the 
lime present. Cool, dilute to 250 cubic centimeters, mix, and 
pass through a dry filter. Evaporate nearly to dryness a 
50-cubic centimeter aliquot of the solution, add 1 cubic centi- 
meter of dilute sulphuric acid (1:1), evaporate to dryness. 



PACKING-HOUSE INDUSTRIES, PART 3 59 

and ignite to whiteness. Maintain a full red heat until the 
residue is perfectly white. Dissolve the residue in hot water, 
using at least 20 cubic centimeters for each decigram of potas- 
sium oxide present, add a few drops of hydrochloric acid and 
platinum solution in excess. Evaporate on the water bath to 
a thick paste. Treat the residue with 80 per cent, alcohol, 
avoiding exposure to ammonia. Filter, wash the precipitate 
thoroughly with 80 per cent, alcohol both by decantation and 
on the filter, continuing the washing after the filtrate is color- 
less. Then wash with 10 cubic centimeters of ammonium 
chloride solution to remove impurities from the precipitate 
and repeat five or six times. Wash again thoroughly with 
80 per cent, alcohol and dry the precipitate for 30 minutes 
at 100° C. Weigh the precipitate of potassium platinic 
chloride, K^PtClf., and multiply by .161 to obtain the weight 
of i^; by .194 to obtain K.^O ; and by .307 to obtain KCL 

71. Determination of Crude Fat or Ether Extract. 

Extract about 2 grams of material that has been dried, with 
anhydrous ether for 16 hours. Dry the extract at the tem- 
perature of boiling water for 30 minutes, cool in a desiccator, 
and weigh; continue at 30-minute intervals this alternate 
drying and weighing until the weight becomes constant. 



